Automated drill bit re-sharpening and verification system

ABSTRACT

A completely automated apparatus for verifying the identity and geometry of drill bits, re-sharpening the cutting tip of a drill bit and re-positioning a locating ring upon the shank portion of the drill bit subsequent to the re-sharpening of the cutting tip thereof. The apparatus comprises a housing having a pair of cassette trays, a pair of grinding assemblies, a pair of optical assemblies, a pair of primary cleaning assemblies, a pair of secondary cleaning assemblies, a pair of inversion assemblies, a pair of workhead assemblies, a bumping assembly, and a loader assembly attached thereto. The workhead and loader assemblies are used to transport drill bits between the cassette trays and other assemblies in a selected sequence which is controlled and coordinated by a programmable control device. The control device is electrically interfaced to each of the assemblies and allows the cutting tip re-sharpening and locating ring re-positioning processes to be conducted simultaneously on at least two drill bits.

RELATED APPLICATIONS

The present application is a continuation-in-part of U.S. applicationSer. No. 09/082,590 entitled AUTOMATED DRILL BIT RE-SHARPENING ANDVERIFICATION SYSTEM filed May 21, 1998.

FIELD OF THE INVENTION

The present invention relates generally to devices or re-sharpeningmachine tools, and more particularly to a completely automated systemwhich verifies the identity and geometry of drill bits, re-sharpens thedrill bits to within closely held tolerances, verifies re-sharpeneddrill bit tolerances, adjusts the positioning of a locating ringdisposed upon the shank of the re-sharpened drill bits, cleans there-sharpened drill bits and subsequently packages the same.

BACKGROUND OF THE INVENTION

The manufacture of printed circuit boards has experienced considerableimprovement over recent years. Technological advancements in chemistry,machinery, and materials have resulted in the ability to consistentlyproduce large volumes of printed circuit boards with dense circuitrypatterns on a highly efficient basis. One particular area of progresshas been in the drilling process associated with printed circuit boards.An individual circuit board typically includes thousands ofsmall-diameter drilled holes which are used to connect variouscomponents to the-board by accommodating the leads or pins thereof, toconnect the circuitry traces of one layer to another, to providereference points for subsequent processing, and to assist in mountingthe complete circuit board within its final housing. In one currentlyknown circuit board manufacturing process, a plurality of circuit boardsare drilled simultaneously by maintaining the circuit boards in acontiguous, overlapped orientation. In another currently knownfabrication technique, several circuit boards are placed on a panel forprocessing, with a single panel typically including tens of thousands ofdrilled holes.

As will be recognized, due to the extremely small diameter of the holestypically drilled in the printed circuit boards, the associated drillbits are formed having small diameter cutting tips and are made of anextremely hard, wear resistant material such as tungsten carbide. Thoughthis material is resistant to wear, after a certain number of drilledholes (“hits”), the drill bit will typically deteriorate and will nolonger be sharp enough to maintain the diameter and tolerancerequirements for subsequent holes. Through experience, circuit boardmanufactures have approximated the rate at which drill bits dull. Basedupon this wear rate, the drill bit is typically replaced after a certainnumber of hits.

During the printed circuit board manufacturing process, the depth towhich the cutting tip of the drill bit penetrates, i.e., extends into,the circuit board(s) must also be tightly controlled. In this respect,the drill bits used to facilitate the drilling operation are typicallyprovided with a locating ring disposed about the shank portion thereofwhich serves as a stop for accurately locating the drill bit, thecollet, or the tool holder of the rotary drilling apparatus. Due to theimportance of tightly controlling the penetration depth of the cuttingtip of the drill bit into the circuit board(s), the distance separatingthe cutting tip from the-locating ring must itself be tightlycontrolled, thus necessitating the precise positioning of the locatingring upon the shank portion of the drill bit.

In view of the difficulty and expense associated with the manufacture ofcarbide drill bits with small diameter cutting tips, once the cuttingtip of the drill bit becomes dull, the same is typically re-sharpenedrather than being discarded. As will be-recognized, due to theimportance of drilling all the holes within the circuit board(s) withinclosely held tolerances, the re-sharpening of the cutting tip of thedrill bit must be accomplished in a precise, highly accurate manner.Additionally, since the re-sharpening procedure often results in aslight loss of length from the cutting tip region of the drill bit, thedistance separating the cutting tip from the locating ring must bemaintained within a certain, tightly controlled range. In this respect,the shortening of the drill bit which occurs as a result of there-sharpening procedure requires that the position of the locating ringupon the shank portion be adjusted so as to once again achieve thedesired separation distance between the locating ring and the sharpenedcutting tip.

The re-positioning of the locating ring upon the shank portion of thedrill bit is tropically accomplished manually through the utilization ofconventional measurement techniques and devices such as calipers.Additionally, the re-sharpening of the cutting tip of the drill bit andsubsequent measurement thereof to ensure compliance with tolerancerequirements are often accomplished manually. However, as will berecognized, such manual re-positioning and re-sharpening techniques areextremely time consuming and thus expensive, and oftentimes do notaccomplish the positioning of the locating ring relative the cutting tipand/or the re-sharpening of the cutting tip with the degree of accuracyneeded to ensure that the subsequent drilling operation will be properlyconducted.

There has yet to be developed in the prior art an completely automatedsystem for accomplishing the verification of identity and differinggeometries of various drill bits and the re-sharpening andre-positioning functions described above. One of the difficulties inautomating the re-sharpening process is that the size and condition ofthe cutting tip of the drill bit often varies. In this respect, thecutting tip may be dirty, worn, undersize in diameter and/or length,chipped, or broken. Additionally, drill bits are typically sent forre-sharpening in large quantities, with such quantities including drillbits that are from different manufacturers, have different dates oforiginal manufacture, are of differing styles and/or series, or arebeing subjected to a first or subsequent re-sharpening procedure.

The present invention specifically addresses the above-describeddeficiencies and obstacles by providing a completely automated systemwhich automatically verifies the identity and geometry of drill bits,re-sharpens the cutting tip of a drill bit to within closely heldtolerances, and accurately adjusts the positioning of the locating ringupon the drill bit subsequent to the re-sharpening of the cutting tipthereof.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided an automatedapparatus for verifying the identity and geometry of drill bits andre-sharpening the drill bit having a shank portion including a locatingring positioned thereupon, and a fluted portion which defines a cuttingtip of the drill bit. In addition to functioning to re-sharpen thecutting tip of the drill bit, the present automated apparatus functionsto adjust the position of the locating ring relative to the cutting tipsubsequent to the re-sharpening thereof.

In the preferred embodiment, the automated apparatus comprises a housingor base table having at least one and preferably a pair of cassettetrays attached thereto, each of which is sized and configured toaccommodate multiple drill bit containers. Each of the drill bitcontainers includes a plurality of drill bits stored therewithin. Alsoattached to the housing is a pair of grinding assemblies, each of whichis used to grind the cutting tip of a drill bit, and a pair of vision oroptical assemblies, each of which is used to conduct an initialverification of the identity and geometry of the drill bit inspection ofthe cutting tip of a drill bit prior to the grinding thereof and a finalinspection of the cutting tip subsequent to the grinding thereof. Inaddition to the grinding and optical assemblies, attached to the housingis a pair of primary cleaning assemblies which are each used forcleaning the cutting tip of a drill bit prior to the initial inspectionthereof, and a pair of secondary cleaning assemblies which are each usedfor cleaning the cutting tip of a drill bit prior to the finalinspection thereof. Also attached to the housing is a pair of inversionassemblies for selectively directing one of the shank portion and thefluted portion of a drill bit generally vertically upwardly, and atleast one bumping assembly which is used for adjusting the position ofthe locating ring or a drill bit relative to its cutting tip subsequentto the final inspection thereof.

The automated apparatus of the present invention further comprises apair of workhead assemblies which are each movably attached to thehousing and used for selectively transporting a drill bit betweenrespective ones of the optical, grinding, and secondary-cleaningassemblies. Also movably or rotatably attached to the housing is arobotic loader assembly of the automated apparatus which is used toselectively transport drill bits from the cassette trays to respectiveones of the inversion assemblies if required by the orientation of thedrill bits within the drill bit containers, from the cassette trays orinversion assemblies to respective ones of the primary cleaningassemblies, from the primary cleaning assemblies to respective ones ofthe inversion assemblies, from the inversion assemblies to respectiveones of the workhead assemblies, from the workhead assemblies to thebumping assembly, and from the bumping assembly back to respective onesof the cassette trays.

In the present automated apparatus, a programmable control device iselectrically interfaced to the grinding, optical, secondary cleaning,inversion, bumping, workhead, and loader assemblies to control andcoordinate the operations thereof in a manner allowing the cutting headre-sharpening and locating ring re-positioning processes to be conductedsimultaneously on at least two drill bits. In this respect, the controldevice is operable to cause the loader assembly to remove the drill bitsfrom each drill bit container one at a time, and return each of thedrill bits to the drill bit container from which it was removedsubsequent to the final inspection of the cutting tip or there-positioning of the locating ring.

In the preferred embodiment, the loader assembly of the automatedapparatus comprises a robotic arm which is rotatable about first, secondand third generally parallel loader axes, and movable linearly (i.e.,upwardly and downwardly) along the third loader axis. Attached to therobotic arm is a gripper which is adapted to receive and releasably holdone or two drill bits, and is pivotally movable relative to the thirdloader axis. The gripper itself comprises a pair of shaft members whichare pivotally connected to the robotic arm. Each of the shaft membershas an aperture extending therethrough which is sized and configured toreceive the shank portion of a drill bit. The gripper further comprisesa rotary actuator member which is connected to the robotic arm andmechanically coupled to the shaft members in a manner wherein themovement of the actuator results in the concurrent pivotal movement ofthe shaft members relative to the robotic arm. In addition to the shaftand actuator members, the gripper comprises an elongate vacuum tubewhich is fluidly connected to the apertures for selectively creatingnegative pressure therewithin. The creation of a vacuum within each ofthe apertures subsequent to the receipt of the shank portion of a drillbit thereinto facilitates the retention of the drill bit within thegripper of the loader assembly.

Each of the optical assemblies of the automated apparatus comprises topand front cameras for generating images which are used to determine theoverall length of the drill bit, the diameter and geometry of thecutting tip thereof, and the condition of the margins thereof. Theimages generated by the top and front cameras are further used to indexthe cutting tip to selected reference points. In addition to the top andfront cameras, each optical assembly further includes an illuminationarray for illuminating the fluted portion and the cutting tip, andcontrol logic which is operative to process and interpret the imagesgenerated by the top and front cameras. The control logic of each of theoptical assemblies also interacts with the control device in a mannerfacilitating the regulation of the movement of each of the workheadassemblies in a prescribed manner based on the generated images.

Each of the grinding assemblies comprises at least one grinder motorhaving a grinder head rotatably connected thereto. The grinder headitself defines a grinding face. Each grinding assembly further comprisesan adjustment mechanism which is attached to the grinder motor and isoperative to selectively move the grinder head into and out of contactwith the cutting tip of the drill bit based upon the level of contactpressure exerted by the cutting tip against the grinding face. Theadjustment mechanism itself comprises a housing having an elongate ballscrew rotatably mounted thereto. Mechanically coupled to the ball screwis a stepper motor which is operative to selectively rotate the ballscrew in either a first direction or a second direction opposite thefirst direction. Additionally, cooperatively engaged to the ball screwis a linear bearing. In the adjustment mechanism, the rotation of theball screw in the first direction facilitates the movement of the linearbearing toward a respective workhead assembly. Conversely, the rotationof the ball screw in the second direction facilitates the movement ofthe linear bearing away from the corresponding workhead assembly. Thegrinder motor is itself attached to the linear bearing.

Each of the primary cleaning assemblies of the automated apparatuscomprises a bath having a quantity of cleaning putty disposed therein.The cutting tip of a drill bit is insertable into and removable fromwithin the cleaning putty of each primary cleaning assembly via theloader assembly. Additionally, each of the secondary cleaning assembliescomprises a base member having a conveyor member movably attachedthereto. The conveyor member is selectively movable between extended andretracted positions relative to the base member, and includes a quantityof cleaning putty disposed thereon. In addition to the base and conveyormembers, each secondary cleaning assembly comprises an indexing memberwhich is attached to the base member and operable to index the conveyormember a prescribed incremental distance when the conveyor member ismoved from its extended position to its retracted position. The cuttingtip of a drill bit is insertable into the cleaning putty of a respectiveone of the secondary cleaning assemblies by a respective one of theworkhead assemblies, with such insertion occurring immediately prior tothe final inspection of the cutting tip by a respective one of theoptical assemblies.

Each of the workhead assemblies of the automated apparatus comprises abase member which is reciprocally moveable relative to the housing alonga first axis. Rotatably connected to the base member is a swivel memberwhich is rotatable about a second axis extending in generallyperpendicular relation to the first axis. Movably attached to the swivelmember is a collet member which is adapted to receive and releasablyhold the shank portion of a drill bit. The collet member is reciprocallymovable along and rotatable about a third axis which extends ingenerally perpendicular relation to the second axis. The insertion of adrill bit into the collet and the removal of the drill bit fromtherewithin is accomplished via the loader assembly. Each workheadassembly further comprises a support number which is attached to thebase member and receives and supports a portion of the collet memberwhen the cutting tip is being ground by a respective one of the grindingassemblies.

The bumping assembly of the automated apparatus comprises a drill seatwhich is attached to the housing for slidably receiving the shankportion of a drill bit. In addition to the drill seat, the bumpingassembly comprises an adjustment mechanism which is attached to thehousing and used for positioning the cutting tip a desired separationdistance from the drill seat, and a reciprocal ram assembly which ismovably attached to the housing and used for selectively bumping thelocating ring into abutting contact with the drill seat subsequent tothe shank portion being inserted into the drill seat and the cutting tipbeing positioned at the separation distance from the drill seat. Thedrill bit is insertable into and removable from within the drill seatvia the loader assembly.

Each of the inversion assemblies of the automated apparatus comprises abase member and a rotatable inversion arm which is attached to the basemember and adapted to receive a drill bit. In addition to the basemember and inversion arm, each of the inversion assemblies comprises alocking pin which is attached to the base member for maintaining thedrill bit within the inversion arm. Also attached to the base member isan air stream generator of the inversion assembly which is used toremove residual putty from the cutting tip of the drill bit within theinversion arm. Drill bits are inserted into and removed from within theinversion arm of each of the inversion assemblies via the loaderassembly.

Further in accordance with the present invention, there is provided anautomated method of re-sharpening a drill bit having a shank portionwhich includes a locating ring positioned thereupon and a fluted portionwhich defines a pair of margins and a cutting tip. The present methodemploys the use of an automated re-sharpening apparatus which includes apair of cassette trays, a pair of grinding assemblies, a pair of opticalassemblies a pair of primary cleaning assemblies, a pair of secondarycleaning assemblies, a pair of workhead assemblies, a bumping assembly,and a loader assembly. In addition to re-sharpening the cutting tip ofthe drill bit, the present method also achieves the re-positioning ofthe locating ring relative to the cutting tip if necessitated by there-sharpening thereof.

The present method comprises the initial step of positioning at leastone, and preferably multiple drill bit containers onto respective onesof the cassette trays, with each of the drill bit containers including aplurality of drill bits stored therewithin. Thereafter, the drill bitsare removed from each drill bit container one at a time via the loaderassembly. Such removal is accomplished by advancing the loader assemblyover the drill bit and into contact with the locating ring positionedupon the shank portion thereof. Thereafter, negative pressure is createdwithin the loader assembly at a level sufficient to retain the drill bittherewithin.

The drill bits may be oriented within each of the drill bit containerssuch that either the shank portion or fluted portion thereof is directedgenerally vertically upwardly. If, during the removal of a drill bitfrom within a respective drill bit container, the loader assembly isadvanced over the fluted portion, the drill bit is thereafter insertedinto the rotatable arm of a respective one of the inversion assembliesvia the loader assembly such that the fluted portion is directedgenerally vertically upwardly. Thereafter, the pressure within theloader assembly is equalized, with the loader assembly then beingretracted away from the drill bit. The inversion arm is then rotatedsuch that the shank portion is directed generally vertically upwardly.Subsequent to this “flipping” of the drill bit, the loader assembly isadvanced over the shank portion thereof and into contact with thelocating ring positioned thereupon. Negative pressure is then againcreated within the loader assembly at a level sufficient to retain thedrill bit therewithin. The drill bit is then removed from within theinversion arm via the loader assembly.

After the drill bit has been inverted and re-grasped by the loaderassembly in the above-described manner, the fluted portion of the drillbit protrudes from the loader assembly. The cutting tip of the drill bitis then inserted into and removed from within the quantity of cleaningputty of one of the primary cleaning assemblies via the loader assembly.If, during the removal of the drill bit from within a respective one ofthe drill bit containers, the loader assembly is advanced over the shankportion of the drill bit rather than the fluted portion thereof, thedrill bit need not be inverted prior to !he cleaning of the cutting tipthereof via a respective one of the primary cleaning assemblies sincethe fluted portion already protrudes from the loader assembly. Rather,subsequent to the removal of the drill bit from within a respective oneof the drill bit containers, the cutting tip thereof is inserted intoand removed from within the quantity of cleaning putty of one of theprimary cleaning assemblies via the loader assembly.

After being cleaned by one of the primary cleaning assemblies, the drillbit is inserted into the rotatable arm of a respective one of theinversion assemblies via the loader assembly such that the shank portionthereof is directed generally vertically upwardly. The pressure withinthe loader assembly is then equalized, with the loader assembly thenbeing retracted from the drill bit. The air stream generator is thenused to blow air onto the cutting tip of the drill bit to remove anyresidual cleaning putty therefrom. Thereafter, the inversion arm isrotated such that the fluted portion of the drill bit is directedgenerally vertically upwardly. The loader assembly is then advanced overthe fluted portion of the drill bit and into contact with the locatingring positioned upon the shank portion thereof. Negative pressure isthen again created within the loader assembly at a level sufficient toretain the drill bit therewithin, with the drill bit then being removedfrom within the inversion arm via the loader assembly.

After being removed from within the inversion assembly, the drill bit istransferred from the loader assembly to a respective one of the workheadassemblies. More particularly, the shank portion of the drill bit isinserted into a respective one of the workhead assemblies via the loaderassembly. Once releasably held within a respective workhead assembly,the fluted portion of each drill bit is inserted into the interior of arespective one of the optical assemblies thereby.

Once inserted into a respective optical assembly, the overall length ofthe drill bit is determined, as is the diameter of the cutting tip andthe condition of the margins. Thereafter, the cutting tip is indexed toa prescribed position. The determination of the overall length of thedrill bit is preferably accomplished by indexing the cutting tip to afirst reference point on a second reference axis generated by thecontrol logic of the optical assembly via the workhead assembly. Thisstep is followed by determining the distance between the first referencepoint and a point of intersection between the first reference axis and asecond reference axis also generated by the control logic of the opticalassembly. The control logic of the optical assembly is further operativeto generate a reference line and a target line, with the step ofindexing the cutting tip to a prescribed position preferably beinginitiated by the generation of the reference line along the cutting tipof the drill bit. Thereafter, the drill bit is rotated via the workheadassembly to adjust the angular orientation of the reference linerelative to a third reference axis generated by the control logic of theoptical assembly to within a prescribed range. The cutting tip is thenindexed to a second reference point on the second reference axis, withthe target line thereafter being generated along one of the margins ofthe fluted portion. Finally, the drill bit is rotated via the workheadassembly as needed to cause the target line to cross the point ofintersection between the first and second reference axes. The drill bitis thereafter removed from within the optical assembly via the workheadassembly.

After the initial evaluation of the fluted portion and the cutting tipof each drill bit has been completed by a respective optical assembly,the cutting tip of each drill bit is ground via a respective one of thegrinding assemblies. In particular, the cutting tip of each drill bit ismoved into contact with a respective grinding assembly via the workheadassembly in which the drill bit is releasably held. After its initialmovement into the grinding assembly, the cutting tip of the drill bit isbacked away therefrom via the workhead assembly, and then rotatedapproximately 180° thereby. Subsequent to such rotation, the cutting tipis then moved back into contact with and thereafter drawn back away fromthe grinding assembly. Importantly, the grinding operation conducted onthe cutting tip of each drill bit by a respective one of the grindingassemblies is governed by the initial evaluation of the fluted portionand cutting tip of the drill bit by the corresponding optical assembly.Additionally, when the cutting tip of each drill bit is moved intocontact with a respective one of the grinding assemblies, a portion ofthe collet member of the associated workhead assembly is advancedthrough and supported by the secure member of the workhead assembly toreduce the vibration of the cutting tip during the grinding process.During each of the grinding operations described above, the grindingassembly may be retracted away from the cutting tip of the drill bit inthe event the contact pressure between the cutting tip and the grindingassembly exceeds a prescribed level.

Subsequent to being ground, the drill bits are carried by the workheadassemblies in which they are releasably held to respective ones of thesecondary cleaning assemblies. As the workhead assembly approaches arespective secondary cleaning assembly, the conveyor member of thesecondary cleaning assembly is actuated to its extended position, thusplacing a portion of the cleaning putty disposed thereon into horizontalalignment with the cutting tip of the drill bit. The cutting tip of thedrill bit is then inserted into the cleaning putty of the secondarycleaning assembly by the associated workhead assembly. The conveyormember of the secondary cleaning assembly is then actuated back to itsretracted position. Importantly, the movement of the conveyor memberback to its retracted position causes the indexing member attached tothe base member of the secondary cleaning assembly to index the conveyormember a prescribed incremental distance. Such movement of the conveyormember causes the cutting tips of subsequently cleaned drill bits to beinserted into different portions of the cleaning putty disposed upon theconveyor member.

After being cleaned by respective ones of the secondary cleaningassemblies, the drill bits are re-inserted by the workhead assembliesinto respective ones of the optical assemblies. Within each opticalassembly, a final evaluation of the drill bit is conducted. In the finalevaluation, the overall length of the drill bit is determined, as is thegeometry of the cutting tip and condition of the margins thereof. Thedetermination of the overall length of the drill bit is accomplished inthe same manner previously described in relation to the initialevaluation. Subsequent to the completion of such measurements, the drillbit is then removed from within the optical assembly via the workheadassembly in which it is releasably held. The final evaluation of eachdrill bit also includes a determination as to whether the locating ringof the drill bit is properly positioned relative to the cutting tipthereof.

If it is determined that the positioning of the locating ring relativeto the cutting tip must be adjusted, the drill bit is transported fromits associated workhead assembly to the bumper assembly via the loaderassembly. In particular, the shank portion of the drill bit is insertedinto a drill seat of the bumping assembly, with the cutting tip thenbeing positioned at a desired separation distance from the drill seat.Thereafter, the locating ring is bumped into abutting contact with thedrill seat. Subsequent to the completion of this bumping operation, thedrill bit is transported from the bumping assembly back to a respectiveone of the cassette trays via the loader assembly. More particularly,the drill bit is returned by the loader assembly to the precise locationin the drill bit container from which it was initially removed. As willbe recognized, if during the final evaluation of the drill bit it isdetermined that the position of the locating ring need not be adjusted,the drill bit is transported directly from the workhead assembly to theproper cassette tray by the loader assembly. Additionally, if during thefinal evaluation of the drill bit it is determined that there is a faultin the geometry of its cutting tip, the drill bit is not transported tothe bumping assembly or to a drill bit container on one of the cassettetrays, but rather is rejected to a separate location by the loaderassembly.

In the present method, the drill bits need not necessarily be removedfrom and returned to the cassette trays, and in particular the drill bitcontainers positioned thereon, but rather may be removed from anypick-up location and returned to any drop-off location. Additionally, inthe present method, data corresponding to the initial and finalevaluations of each of the drill bits processed by the re-sharpeningapparatus is preferably stored within the control device. This data maybe used to facilitate the generation of a statistical process controlreport regarding the processed drill bits. This data may also be used togenerate a used drill profile which may itself be used to adjust themanner in which the cutting tips of subsequently processed drill bitsare ground by the re-sharpening apparatus. Moreover, the data generatedand stored in relation to the drill bits may be used to facilitate thesorting thereof in a manner wherein the drill bits are transported torespective ones of multiple drop-off locations according to the finalevaluations related thereto.

In the above-described steps of the present method wherein the loaderassembly is used to transport the drill bit between the workheadassemblies and the bumping assembly and between the bumping assembly andrespective ones of the cassette trays, such transport is accomplished inthe same manner previously described in relation to the removal of thedrill bit from one of the cassette trays via the loader assembly, theinsertion of the drill bit into and the removal of the drill bit fromwithin a respective one of the inversion assemblies by the loaderassembly both prior and subsequent to the initial cleaning of thecutting tip thereof, and the transfer of the drill bit from the loaderassembly to a respective one of the workhead assemblies. Moreparticularly, the loader assembly is initially advanced over the flutedportion of the drill bit and into contact with the locating ringpositioned upon the shank portion. Thereafter, negative pressure iscreated within the loader assembly at a level sufficient to retain thedrill bit therewithin. After the shank portion of the drill bit has beeninserted into either a workhead assembly, the drill seat of the bumpingassembly, or the drill bit container, the pressure within the loaderassembly is equalized, with the loader assembly then being retractedfrom the drill bit.

For each drill bit to be inserted into and removed from within theinversion arm of an inversion assembly, the drill seat of the bumpingassembly, and the drill bit container, the drill bit must be maintainedin a generally vertical orientation by the loader assembly. However, tobe inserted into and removed from within each workhead assembly, thedrill bit must be maintained in a generally horizontal orientation bythe loader assembly. As such, the loader assembly is adopted to pivot toaccomplish the extension of the drill bit either vertically orhorizontally as needed.

BRIEF DESCRIPTION OF THE DRAWINGS

These, as well as other features of the present invention, will becomemore apparent upon reference to the drawings wherein:

FIG. 1 is a perspective view of a drill bit container used with there-sharpening apparatus of the present invention, illustrating themanner in which multiple dr-ill bits are stored therewithin;

FIG. 2 is a front perspective view of the re-sharpening apparatus of thepresent invention;

FIG. 2 a is a perspective view of one of the cassette trays of thepresent re-sharpening apparatus, illustrating the manner in whichmultiple drill bit containers are positioned thereupon;

FIG. 3 is a top view of the re-sharpening apparatus of the presentinvention;

FIG. 4 is a partial cross-sectional view of one of the shaft members ofthe gripper of the loader assembly of the present re-sharpeningapparatus;

FIG. 4 a is a side elevational view of the gripper of the loaderassembly, illustrating the manner in which it is pivotally movablerelative to the robotic arm of the loader assembly;

FIG. 4 b is a perspective view of the gripper of the loader assembly;

FIG. 5 is a perspective view of one of the inversion assemblies of thepresent re-sharpening apparatus, illustrating the manner in which adrill bit is maintained therein;

FIG. 6 is a perspective view of one of the workhead assemblies of thepresent re-sharpening apparatus;

FIG. 6 a is a partial side elevational view of the collet member of theworkhead assembly shown in FIG. 6;

FIG. 7 is a cut-away perspective view of one of the optical assembliesof the present re-sharpening apparatus, illustrating the manner in whicha drill bit is inserted into the interior thereof via one of theworkhead assemblies,;

FIGS. 7 a-7 d are step-by-step illustrations of the initial evaluationprocedure conducted on a drill, bit by each optical assembly of thepresent re-sharpening apparatus;

FIG. 8 is a front perspective view of one of the-grinding assemblies ofthe present re-sharpening apparatus;

FIG. 8 a is a perspective view of one of the secondary cleaningassemblies of the present re-sharpening apparatus;

FIG. 9 is a partial cross-sectional view of the bumping assembly of thepresent re-sharpening apparatus;

FIGS. 10 a-10 c are step-by-step illustrations of the final inspectionprocedure conducted on a drill bit by each optical assembly of thepresent re-sharpening apparatus;

FIGS. 11 a-11 n are step-by-step illustrations of the preferred sequenceof operations conducted by the present re-sharpening apparatus;

FIGS. 12 a-12 j are end views of the cutting tip of a drill bit,illustrating various possible conditions thereof subsequent to thecompletion of operations conducted by the present re-sharpeningapparatus; and

FIG. 13 is a rear perspective view of one of the two adjustment unitswhich may be integrated into each of the two grinding assemblies of thepresent re-sharpening apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings wherein the showings are for purposes ofillustrating a preferred embodiment of the present invention only, andnot for purposes of limiting the same, FIGS. 2 and 3 illustrate thecompletely automated drill bit verification and re-sharpening apparatus10 constructed in accordance with the present invention. As will bedescribed in more detail below, the apparatus 10 is utilized toautomatically verify the identity and geometry of a drill bit 16 andre-sharpen the cutting tip 12 included on the distal end of the flutedportion 14 of a drill bit 16 (shown in FIG. 1). The drill bit 16 furtherincludes a cylindrically configured shank portion 18 which transitionsinto the fluted portion 14 via a tapered region 20. Positioned upon theshank portion 18 is an annular locating or setting ring 22. The locatingring 22, which is placed along the shank portion 18 at a standardizedposition for subsequent use, is normally located about 0.8 inches fromthe end 24 of the shank portion 18, and is frictionally maintained atthis position upon the shank portion 18.

FIG. 12 j illustrates a cutting tip 12 having an optimum point geometry.As seen in FIG. 12 j, the cutting tip 12 of the drill bit 16 includes achisel edge 200 which defines the distal-most point of the cutting tip12. In addition to the chisel edge 200, the cutting tip 12 includes anopposed pair of cutting edges 202. The lateral distance between thecutting edges 202 defines the web thickness WT of the cutting tip 12. InFIG. 12 j, a center line CL is shown as bisecting the cutting tip 12into two (2) identical halves. Those portions of the cutting tip 12between the center line CL and the straight sections of the cuttingedges 202 define the primary faces 204 of the cutting tip 12. Thoseportions of the cutting tip 12 between the center line CL and thearcuate sections of the cutting edges 202 define the secondary faces 206of the cutting tip 12. As seen in FIG. 7 c, the fluted portion 14 of thedrill bit 16 includes a pair of margins, each of which are of a marginwidth MW. The margins extend distally to the cutting tip 12 of the drillbit 16.

As previously explained, the drill bit 16 is typically fabricated fromcarbide or tungsten carbide, and utilized in relation to the manufactureof printed circuit boards. The drill bit 14, and in particular thefluted portion 14 thereof, is used to form a plurality of small diameterholes within a single circuit board or a plurality of overlapped circuitboards for accommodating the pins or leads of the electrical componentswhich are to be subsequently interfaced to the circuit board(s). Inaddition to the diameters of the holes within the circuit board(s)needing to be held within close tolerances, the depth to which thecutting tip 12 of the drill bit 16 penetrates (i.e., is extended into)the circuit board(s) must also be accurately controlled to insure properdrilling tolerances. Such depth control is typically accomplishedthrough the axial positioning of the frictionally mounted locating ring22 upon the shank portion 18. In this respect, the extension of theshank portion 18 into the collet or tool holder of a drilling apparatus(not shown) is limited by the abutment of the locating ring 22thereagainst. Since the locating ring 22 serves as a “stop” forcontrolling the length of the drill bit 16 which extends from the toolholder, the distance D1 separating the cutting tip 12 from the locatingring 22 must be maintained within a certain, close tolerance range toinsure proper circuit board drilling.

Due to the expense associated with the manufacture of the drill bit 16,after prolonged use, the cutting tip 12 is preferably re-sharpenedrather than the drill bit 16 being discarded. The re-sharpening of thecutting tip 12 generally results in a decrease in the length of thefluted portion 14, thus lessening the distance D1 separating the cuttingtip 12 from the locating ring 22. As such, after the re-sharpeningprocedure has been completed, the position of the locating ring 22 uponthe shank portion 18 must be adjusted to re-achieve the proper distanceD1 separating the cutting tip 12 from the locating ring 22. As alsopreviously explained, in the prior art, the re-sharpening of the cuttingtip 12 as well as the re-positioning of the locating ring 22 upon theshank portion 18 is typically done manually or semi-manually through theuse of various independent conventional grinding and measurement systemsand techniques. However, the use of these prior art methods, in additionto being time-consuming and costly, often does not facilitate therequired level of accuracy in the finished configuration of the cuttingtip 12 and/or the distance D1 separating the cutting tip 12 from thelocating ring 22.

Drill Bit Container

As further seen in FIG. 1, for processing by the present apparatus 10,drill bits 16 (including the locating rings 22 positioned thereupon) arepreferably stored in a drill bit container 26. The drill bit container26 comprises a base 28 having a cover 30 pivotally connected thereby viaa pair of hinges 32. To secure the cover 30 to the base 28, a first tab34 of the cover 30 mates with a second tab 36 of the base 28. As such,the drill bit container 26 can assume either an opened position or aclosed position, and is shown in FIG. 1 in its opened position.

The base 28 of the drill bit container 26 defines a generally flat topsurface 38 having a plurality of drill bit receiving holes 40 disposedtherein. The drill bit receiving holes 40 are specifically arranged inthe top surface 38, and are provided in alternately off-set rows forpurposes of reducing the overall size requirement for the drill bitcontainer 26. Each of the drill bit receiving holes 40 has a diameterwhich is large enough to allow the shank portion 18 of the drill bit 16to pass therethrough. However, each drill bit receiving hole 40 issmaller in diameter than the locating ring 22. As such, the insertion ofthe shank portion 18 axially into a respective one of the holes 40 islimited by the abutment of the lower surface of the locating ring 22against the top surface 38 of the base 28. As such, the majority of theshank portion 18 resides below the top surface 38, with the flutedportion 14 projecting generally perpendicularly upwardly therefrom.Although the particular container 26 illustrated herein is manufacturedby Tycom Corp. of Santa Ana, Calif., the assignee of this patentapplication, those of ordinary skill in the art will recognize thatocher containers 26 manufactured by alternative companies may beutilized in the present invention and are clearly contemplated herein.

The drill bit container 26 used in conjunction with the apparatus 10 maybe of a standard design, or alternatively of any special design asrequired by a customer. Additionally, the drill bits 16 need not beinserted into respective ones of the receiving holes 40 such that thefluted portions 14 thereof project generally perpendicularly upwardlyfrom the top surface 38. Rather, as further seen in FIG. 1, the flutedportion 14 of each drill bit 16 may be axially inserted into arespective one of the holes 40, with such insertion being limited by theabutment of the upper surface of the locating ring 22 against the topsurface 38 of the base 28. In this orientation, the shank portion 18 ofthe drill bit 16 will project generally perpendicularly upwardly fromthe top surface 38.

Apparatus Housing

Referring now to FIGS. 2 and 3, the apparatus 10 of the presentinvention comprises a base table or housing 42 which defines a planartop surface 44 having a generally rectangular configuration. The housing42 is preferably modularly configured, and includes a center section 42a and a pair of identically configured end sections 42 b, 42 c which areabutted against respective ones of opposed sides of the center section42 a. The top surfaces of the center and end sections 42 a, 42 b, 42 ccollectively define the top surface 44. Attached to the front of thehousing 42, and more particularly respective ones of the end sections 42b, 42 c thereof, is a pair of control panels 46, at least one of whichhouses a programmable control device, the use of which will be describedin more detail below. Attached to the top surface of the center section42 a is a rectangularly configured support plate 50. Additionally,attached to the top surface of each of the end sections 42 b, 42 c is apair of generally rectangular support blocks 48, i.e., two (2) pairs ofthe support blocks 48 are attached to the top surface 44. One pair ofopposed sides of the support plate 50 are abutted against respectivepairs of the support blocks 48, with the remaining pair of opposed sidesbeing substantially flush with respective ones of the longitudinal sidesof the center section 42 a of is the housing 42. The support blocks 48and support plate 50 each define generally planar top surfaces.

Cassette Trays

Referring now to FIGS. 2, 2 a and 3, the apparatus 10 of the presentinvention comprises a pair of elongate, generally rectangular cassettetrays 54 which are attached to the generally planar top surfaces ofrespective pairs of the support blocks 48. As seen in FIGS. 2 and 3, thewidth dimensions of the identically configured cassette trays 54 aresubstantially identical to those of the support blocks 48 to which theyare attached. In this respect, the longitudinal and lateral sides ofeach cassette tray 54 are substantially flush with the correspondingsides of the support blocks 48 to which it is attached.

In the apparatus 10, each cassette tray 54 is a frame having a pluralityof generally rectangular, equally sized openings 56 formed therein. Theopenings 56 are each defined by frame walls 58 which project upwardlyfrom a base 60. Importantly, each of the openings 56 has a configurationwhich is complementary to that of the base 28 off the drill bitcontainer 26. In this respect, as seen in FIG. 2 a, each opening 56 issized to partially receive the base 28 of a drill bit container 26 andhold the same in a set position. As also seen in FIG. 2 a, drill bitcontainers 26 may be placed within the openings 56 in a pattern whereinan opening 56 adjacent the base 28 of each drill bit container 26 isused to accommodate the cover 30 when the drill bit container 26 isopened. However, those of ordinary skill in the art will recognize thatthe bases 28 of drill bit containers 26 may be inserted into all of theopenings 56 at one time provided that the covers 30 are detachedtherefrom.

Loader Assembly

Referring now to FIGS. 2, 3, 4, 4 a and 4 b, the apparatus 10 of thepresent invention includes a robotic loader assembly 62 which is movablyor rotatably attached to the support plate 50 and is used to removedrill bits 16 one at a time from within the drill bit containers 26positioned upon the cassette trays 54, and return each drill bit 16 tothe precise location within the drill bit container 26 from which it wasremoved subsequent to the re-sharpening of its cutting tip 12 andre-positioning of its locating ring 22. The loader assembly 62 is alsoused to transport drill bits 16 between various assemblies of theapparatus 10, as will be described in more detail below.

The loader assembly 62 comprises a robotic arm having a generallyL-shaped first arm segment 64 which is rotatably attached to a basemember 65 of the loader assembly 62. The base member 65 is itselfattached to the top surface of the support plate 50 in relative closeproximity to the back edge thereof. As seen in FIG. 2, the first armsegment 64 is rotatable relative to the base member 65 about a firstloader axis LA1 which extends in generally perpendicular relation to thetop surface of the support plate 50. In addition to the first armsegment 64, the robotic arm comprises a second arm segment 66 which isrotatably connected to the distal end of the horizontally extendingportion of the first arm segment 64 and is rotatable about a secondloader axis LA2 relative thereto. As further seen in FIG. 2, the secondloader axis LA2 extends in generally parallel relation to the firstloader axis LA1.

In addition to the first and second arms segments 64, 66, the roboticarm of the loader assembly 62 comprises a third arm segment 67 which isrotatably connected to the end of the second arm segment 66 oppositethat connected to the first arm segments 64. The third arm segment 67 isrotatable about a third loader axis LA3 relative to the second armsegment 66. The third loader axis LA3 itself extends in generallyparallel relation to the first and second loader axes LA1, LA2. Inaddition to being rotatable about the third loader axis LA3, the thirdarm segment 67 of the robotic arm is movable linearly or vertically(i.e., upwardly and downwardly) therealong. Though not shown, therobotic arm of the loader assembly 62 includes internal components whichallows the first arm segment 64 to be rotated about the first loaderaxis LA1, the second arm segment 66 to be rotated about the secondloader axis LA2, and the third arm segment 67 to be rotated about ormoved along the third loader axis LA3.

In addition to the robotic arm, the loader assembly 62 comprises agripper 70 which is attached to the lower end of the third arm segment67 of the robotic arm. The gripper 70 comprises a gripper housing 71 ahaving a pair of gripper arms 71 b extending downwardly therefrom inspaced, generally parallel relation to each other. The gripper 70further comprises a pair of shaft members 72 which are pivotallyconnected to respective ones of the gripper arms 71 b. Moreparticularly, each of the shaft members 72 extends partially between aspaced pair of flange portions defined by a respective gripper arm 71 b.Extending longitudinally through each shaft member 72 is an aperture 74,at least a portion of which has a diameter slightly exceeding thediameter of the shank portion 18 of the drill bit 16. Fluidly connectedto each of the apertures 74 is an elongate, flexible vacuum tube 76 ofthe loader assembly 62 which is also connected to a vacuum pump thereof.When activated, the vacuum pump facilitates the creation of a vacuumwithin each of the apertures 74 for reasons which will be described inmore detail below.

In addition to the shaft members 72, the gripper 70 comprises anactuator member 78 which is used to facilitate the reciprocal pivotalmovement of the shaft members 72 relative to the third loader axis LA3.The actuator member 78 preferably comprises a pneumatic cylinder, thebody of which is pivotally connected to one of the gripper arms 71 b.Extending axially from the body is a piston rod, the distal end of whichis mechanically coupled to the pivot pin used to pivotally connected theshaft members 72 to the gripper arms 71 b and each other.

As seen in FIGS. 4 and 4 a, the shaft members 72 of the gripper 70, inaddition to having the capacity to rotate about and travel verticallyalong the third loader axis LA3 by virtue of the connection of thegripper 70 to the third arm segment 67, may also be pivotedapproximately 90° to a horizontal orientation by the actuator member 78so as to extend along a gripper axis GX which is generally perpendicularto the third loader axis LA3. In this respect, the advancement of thepiston rod of the actuator member 78 from the body thereof facilitatesthe upward pivotal movement of the shaft members 72 from a verticalorientation extending along the third loader axis LA3 (as shown in FIGS.4 and 4 b) to a horizontal orientation extending along the gripper axisGX (as shown in FIG. 4 a). Conversely, the retraction of the piston rodback into the cylinder facilitates the downward pivotal movement of theshaft members 72 and the return thereof to their extension along thethird loader axis LA3. The importance of the ability to extend the shaftmembers 72, and in particular their apertures 74, along the gripper axisGX will be described in more detail below.

As is apparent from the foregoing description of the loader assembly 62,the shaft members 72 of the gripper 70 thereof may be maneuvered to aposition above virtually any location upon the top surface 44 of thehousing 42 by the robotic arm. Importantly, the configuration of the iscassette trays 54 and their attachment to the support blocks 48 is suchthat a drill bit 16 disposed within any drill bit receiving hole 40 of adrill bit container 26 stored within any opening 56 of the cassettetrays 54 is accessible by the gripper 70 of the loader assembly 62, andin particular either of the shaft members 72 thereof.

As further seen in FIG. 4, the “grasping” of a drill bit 16 by theloader assembly 62 when the drill bit 16 is vertically oriented with thefluted portion 14 thereof projecting upwardly is accomplished byinitially maneuvering one of the shaft members 72 via the robotic armsuch that the aperture 74 extending therethrough is coaxially alignedwith the fluted portion 14 of the drill bit 16. Thereafter, the shaftmember 72 is moved vertically downward along the third loader axis LA3and advanced over the fluted portion 14 and tapered region 20 of thedrill bit 16, with such downward advancement being terminated when theshaft member 72 contacts the locating ring 22 of the drill bit 16.Thereafter, the vacuum pump of the loader assembly 62 is activated so asto create negative pressure within the aperture 74. Such negativepressure of vacuum causes the drill to be retained within the shaftmember 72 when the same is moved upwardly along or rotated about thethird loader axis LA3 by the third arm member 67 of the robotic arm. Aswill be recognized, the equalization of pressure within the aperture 74as occurs when the vacuum pump is deactivated results in the immediaterelease of the drill bit 16 from within the shaft member 72.

The “grasping” of the drill bit 16 by the loader assembly 62 when thedrill bit 16 is vertically oriented with the shank portion 18 thereofprojecting upwardly is accomplished in the previously described manneras well. In this respect, one of the shaft members 72 of the gripper 70is initially maneuvered such that the aperture 74 extending therethroughis coaxially aligned with the shank portion 18 of the drill bit 16.Thereafter, the shaft member 72 is moved vertically downward along thethird loader axis LA3 and advanced over the shank portion 18, with suchdownward advancement being terminated when the shaft member 72 contactsthe locating ring 22 of the drill bit 16. Once again, the vacuum pump ofthe loader assembly 62 is activated so as to create negative pressurewithin the aperture 74 which causes the drill bit 16 to be retainedwithin the shaft member 72. The equalization of pressure within theaperture 74 resulting from the deactivation of the vacuum pumpfacilitates the immediate release of the drill bit 16 from within theshaft member 72.

As is apparent from FIG. 4 a, the “grasping” of a drill bit 16 by theloader assembly 62 when the drill bit 16 is horizontally oriented isaccomplished by maneuvering one of the shaft members 72 via the roboticarm such that when the shaft member 72 is pivoted upwardly by theactuator member 78, the gripper axis GX is coaxially aligned with thedrill bit 16, and in particular the fluted portion 14 thereof.Thereafter, the shaft member 72 is moved horizontally and advanced overthe fluted portion 14 and tapered region 20 of the drill bit 16, withsuch horizontal advancement being terminated when the shaft member 72contacts the locating ring 22 of the drill bit 16. The activation of thevacuum pump of the loader assembly 62 retains the drill bit 16 withinthe shaft member 72 in the previously described manner.

Primary Cleaning Assemblies

Referring now to FIGS. 2 and 3, the apparatus 10 of the presentinvention further includes a pair of identically configured primarycleaning assemblies 80 which are each used to facilitate the cleaning ofthe cutting tip 12 of a drill bit 16 prior to the grinding orre-sharpening thereof. Although not by limitation, in the preferredembodiment, the primary cleaning assemblies 80 each comprise arectangularly configured bath or container 82 which is attached to arespective one of the support blocks 48, and more particularly thelongitudinal side thereof disposed adjacent the support plate 50. Eachof the baths 82 contains a quantity of cleaning putty 84.

In the apparatus 10, if a drill bit 16 has initially been grasped by ashaft member 72 of the gripper 70 via the advancement of the shaftmember 72 over the shank portion 18, the cutting tip 12 of the drill bit16 is cleaned immediately subsequent to the removal of the drill bit 16from within a drill bit container 26. Such cleaning is accomplished bymaneuvering the loader assembly 62 such that the shaft mender 72, andmore particularly the fluted portion 14 of the drill bit 16 protrudingtherefrom, is vertically aligned with the cleaning putty 84 of one ofthe primary cleaning assemblies 80. Thereafter, the shaft member 72 ismoved downwardly along the third loader axis LA3 by the third armsegment 67 of the robotic arm so as to facilitate the insertion of thecutting tip 12 of the drill bit 16 into the quantity of cleaning putty84. The shaft member 72 is then moved upwardly along the third loaderaxis LA3 by the third arm segment 67 so as to facilitate the removal ofthe cutting tip 12 from within the cleaning putty 84. It will berecognized by those skilled in the art that alternative cleaning systemssuch as laser systems; carbon dioxide systems; fluidic bath systems andthe like are expressly contemplated herein.

As will be recognized, if the drill bit 16 has been grasped by one ofthe shaft members 72 of the gripper 70 in the manner shown in FIG. 4(i.e., the shaft member 72 is advanced over the fluted portion 14 of thedrill bit 16), the drill bit 16 must be inverted to accomplish thecleaning of the cutting tip 12 thereof via one of the primary cleaningassemblies 80. Such inversion is accomplished through the use of one ofthe inversion assemblies of the apparatus 10 as will be described inmore detail below.

Inversion Assemblies

Referring now to FIGS. 2, 3 and 5, the apparatus 10 of the presentinvention further includes a pair of identically configured inversionassemblies 85 which, as will be discussed in more detail below, are eachused to facilitate the selective inversion or flipping of a drill bit16. The inversion assemblies 85 each comprise a base member 86 which isattached to the top surface of the support plate 50. Rotatably connectedto the base member 86 is an inversion arm 87 which extends in agenerally horizontal direction. The inversion arm 87 is rotatablerelative to the base member 86 via a rotary actuator (not shown)disposed therewithin. Attached to the distal end of the inversion arm 87is a holder block 88 having an aperture extending therethrough which issized to have a diameter slightly exceeding that of the locating ring 22positioned upon a drill bit 16.

Each inversion assembly 85 further comprises an elongate locking pin 89which is movably attached to the base member 86 and defines a distal endwhich is reciprocally movable into and out of the aperture extendingthrough the holder block 88. Also attached to the base member 86 is anair stream generator 90 which is adapted to direct a high pressure airstream against the cutting tip 12 of a drill bit 16 for reasons whichwill be discussed in more detail below.

As indicated above, if the shaft member 72 of the gripper 70 hasinitially been advanced over the fluted portion 14 of a drill bit 16 andinto contact with the locating ring 22, the drill bit 16 must beinverted via one of the inversion assemblies 85 to allow the cutting tip12 thereof to be initially cleaned by one of the primary cleaningassemblies 80. Such inversion is accomplished by maneuvering the shaftmember 72 via the robotic arm of the loader assembly 62 such that theshank portion 18 of the drill bit 16 protruding therefrom is coaxiallyaligned with the aperture extending through the holder block 88 of oneof the inversion assemblies 85. Thereafter, the shaft member 72 is moveddownwardly by the third arm segment 67 of the robotic arm along thethird loader axis LA3 so as to facilitate the insertion of the shankportion 18 into the aperture of the holder block 88.

After the drill bit 16 has been inserted into the holder block 88, theoperation of the inversion assembly 85 is initiated by the actuation ofthe locking pin 89 so as to cause the same to move into engagement withthe shank portion 18 of the drill bit 16. As will be recognized, theengagement of the distal end of the locking pin 89 to the shank portion18 effectively locks the drill bit 16 within the holder block 88. Theequalization of the pressure level within the shaft member 72 andretraction thereof from the drill bid 16 (i.e., upward movement of theshaft member 72 along the third loader axis LA3) occurs subsequent tothe engagement of the locking pin 89 to the shank portion 18 of thedrill bit 16.

As will be recognized, subsequent to the locking of the drill bit 16within the holder block 88 and retraction of the-gripper 70 therefrom,the fluted portion 14 of the drill bit 16 projects generally verticallyupwardly. Thereafter, the inversion arm 87 of the inversion assembly 85is rotated approximately 180° by the rotary actuator so as to cause theshank portion 18 of the drill bit 16 to be directed generally verticallyupwardly. Subsequent to such inversion, the robotic arm of the loaderassembly 62 is used to maneuver one of the shaft members 72 of thegripper 70 such that the aperture 74 thereof is coaxially aligned withthe shank portion 18 of the drill bit 16. The shaft member 72 is thenmoved downwardly along the third loader axis LA3 by the third armsegment 67 and advanced over the shank portion 18 of the drill bit 16.Upon the creation of a vacuum within the aperture 74 sufficient tomaintain the drill bit 16 therewithin, the locking pin 89 of theinversion assembly 85 is retracted so as to remove the distal endthereof from its engagement to the shank portion 18. Such disengagementallows the drill bit 16 to be removed from within the holder block 88 bythe upward movement of the shaft member 72 along the third loader axisLA3. As will be recognized, upon the removal of the drill bit 16 fromwithin the holder block 88, the fluted portion 14 of the drill bit 16protrudes from the shaft member 72, thus allowing the cutting tip 12 tobe cleaned via one of the primary cleaning assemblies 80 in theabove-described manner.

In the apparatus 10 of the present invention, each drill bit 16 must beinverted via one of the inversion assemblies 85 subsequent to thecutting tip 12 thereof being cleaned via one or the primary cleaningassemblies 80 in the above-described manner. In this respect, after thecutting tip 12 has been initially cleaned, the drill bit 16 must begrasped by the gripper 70 of the loader assembly 62 such that the shankportion 18 rather than the fluted portion 14 protrudes from one of theshaft members 72.

The inversion process following the initial cleaning of the cutting tip12 is accomplished by maneuvering the shaft member 72 having the justcleaned drill bit 16 therewithin such that the fluted portion 14 of thedrill bit 16 is coaxially aligned with the aperture extending throughthe holder block 88 of one of the inversion assemblies 85. Thereafter,the shaft member 72 is moved downwardly along the third loader axis LA3by the third arm segment 67 of the robotic arm so as to facilitate theinsertion of the fluted portion 14 into the aperture of the holder block88. After the fluted portion 14 has been advanced through the apertureof the holder block 88, the locking pin 89 is actuated so as to causethe distal end thereof to extend into engagement with the shank portion18 of the drill bit 16. As explained above, the engagement of the distalend of the locking pin 89 to the shank portion 18 effectively locks thedrill bit 16 within the holder block 88. The shaft member 72 is thenmoved upwardly along the third loader axis LA3 by the third arm segment67 so as to retract the same from the drill bit 16.

As will be recognized, when the drill bit 16 is locked within the holderblock 18 and gripper 70 of the loader assembly 62 retracted therefrom,the shank portion 18 is directed generally vertically upwardly, with thefluted portion 14 being directed generally vertically downwardly. Theair stream generator 90 of the inversion assembly 85 is then activated,and is caused to direct a high pressure air stream against the cuttingtip 12 of the drill bit 16 in the manner shown in FIG. 5. Importantly,the impingement of air against the cutting tip 12 effectively removesany residual cleaning putty therefrom. Thereafter, the inversion arm 87of the inversion assembly 85 is rotated approximately 180° so as tocause the fluted portion 14 to be directed generally verticallyupwardly.

Subsequent to the inversion of the drill bit 16, one of the shaftmembers 72 of the gripper 70 is maneuvered such that the aperture 74thereof is coaxially aligned with the fluted portion 14. The shaftmember 72 is then moved downwardly along the third loader axis LA3 viathe third arm segment 67 of the robotic arm and advanced over the flutedportion 14. The vacuum is then created within the aperture 74 at a levelsufficient to maintain the drill bit 16 therewithin. Thereafter, thelocking pin 89 of the inversion assembly 85 is retracted or disengagedfrom the shank portion 18, thus allowing the drill bit 16 to be removedfrom within the holder block 88 by the upward movement of the shaftmember 72 along the third loader axis LA3 by the third arm segment 67 ofthe robotic arm. As will be recognized, upon the removal of the drillbit 16 from the inversion assembly 85, the shank portion 18 thereofprotrudes from one of the shaft members 72 of the gripper 70.

Workhead Assemblies

Referring now to FIGS. 2, 3, 6 and 6 a, the apparatus 10 furthercomprises an identically configured pair of workhead assemblies 96, eachof which is used to transport a drill bit 16 between other assemblies ofthe apparatus 10 as will be described in more detail below. Each of theworkhead assemblies 96 comprises a generally rectangular base member 98which is reciprocally moveable along a base member axis BX (as shown inFIG. 3). The base member axes BX of the workhead assemblies 96 extend inco-planar, parallel relation to each other.

The movement of the base member 98 along its base member axis BX isfacilitated by an actuator 100 of the workhead assembly 96. As best seenin FIG. 2, the actuator 100 of each workhead assembly 96 preferablycomprises a pneumatic cylinder, the body of which is attached to the topsurface 44 of the housing 42 and disposed underneath a respective one ofthe cassette trays 54. Extending axially from the body is an elongatepiston rod, the distal end of which is attached to the base member 98.As will be recognized, the advancement of the piston rod of the actuator100 from within the body thereof results in the movement of the basemember 98 along its base member axis BX away from the cassette trays 54.Conversely, the retraction of the piston rod of the actuator 100 intothe body thereof results in the movement of the base member 98 along itsbase member axis BX toward the cassette trays 54. Those of ordinaryskill in the art will recognize that the actuator 100 used to facilitatethe movement of the base member 98 along its base member axis BX maycomprise devices other than for a pneumatic cylinder.

In addition to the base member 98 and actuator 100, each workheadassembly 96 comprises a swivel member 102 having a swivel member housing103 which is rotatably connected to the base member 98 via a bearing101. The swivel member 102 is rotatable about a swivel member axis whichextends in generally perpendicular relation to the base member axis BX,and thus extends in generally parallel relation to the first, second andthird loader axis LA1, LA2, LA3. The rotation of the swivel member 102relative to the base member 98 is accomplished by the selectiveactivation of a first stepper motor 104 thereof which extends from theswivel member housing 103. The rotation of the swivel member 102relative to the base member 98 may alternatively be accomplished throughthe use of a pneumatic cylinder rather than the first stepper motor 104.

Each workhead assembly 96 further comprises a collet member 106 which isattached to the swivel member 102. The collet member 106 includes acollet member housing 107 having a cylindrically configured collet shaft108 extending therefrom. Attached to the distal end of the collet shaft108 is a locking sleeve 111 which accommodates a collet head 110. In theworkhead assembly 96, the collet shaft 108, and hence the collet head110, is reciprocally movable relative the collet member housing 107along a collet axis CX (shown in FIG. 6). In addition to being movablealong the collet axis CX, the collet shaft 108 is rotatable thereabout.The movement of the collet shaft 108 along and about the collet axis CXis facilitated by a second stepper motor 112 of the collet member 106which extends from the collet member housing 107 thereof. The colletaxis CX extends in generally parallel relation to the plane of the topsurface 44 of the housing 42 throughout the rotation of the swivelmember 102. The first and second stepper motors 104, 112 may compriseservo motors, or linear servo motors. Since the second stepper motor 112facilitates the rotation of the collet shaft 108 about the collet axisCX, such motor provides a prescribed rotational positioning of thecutting tip 12 of the drill bit 16 as will be described in more detailbelow.

Referring now to FIGS. 4, 4 a, 6 and 6 a, in the apparatus 10, a drillbit 16 is insertable into and removable from within the collet head 110of each workhead assembly 96 by the loader assembly 62. In this respect,the collet head 110 is sized and configured to slidably receive theshank portion 18 of a drill bit 16, with the advancement of the shankportion 18 into the collet head 110 being limited by a stopper withinthe collet head 110 which is adjusted so that only about one-eighth ofan inch of the shank portion 18 of the drill bit 16 is inserted into andlocked within the collet head 110. Since the collet axis CX extendshorizontally, a drill bit 16 held S vertically within a shaft member 72of the gripper 70 in the above-described manner must be pivoted toextend along the gripper axis GX (as shown in FIG. 4 a) prior to beinginsertable into the collet head 110. In addition to the shaft member 72being pivoted by the actuator member 78 to facilitate the extension ofthe drill bit 16 along the gripper axis GX, the shaft member 72 mustalso be maneuvered by the loader assembly 62 such that the gripper axisGX is coaxially aligned with the collet axis CX in order for the shankportion 18 to be insertable into the collet head 110. The gripper axisGX must also be coaxially aligned with the collet axis CX for the shaftmember 72 to be advanced over the fluted portion 14 of the drill bit 16and into contact with the locating ring 22 to facilitate the removal ofthe drill bit 16 from within the collet head 110.

As best seen in FIG. 6, each workhead assembly 96 further comprises anelongate support member 114 which is attached to the base member 98.Extending through the support member 14 in close proximity to the topend thereof is an aperture 116 which is sized and configured to slidablyreceive the locking sleeve 111. As will be described in more detailbelow, the locking sleeve 111 is slidably advanced into the aperture 116as part of the process of re-sharpening the cutting tip 12 of the drillbit 16 so as to allow the support member 14 to guide and preventexcessive vibration of the drill bit 16 within the collet head 110during the re-sharpening process.

Optical Assemblies

Referring now to FIGS. 2, 3 and 7, the apparatus 10 further comprises apair or vision or optical assemblies 118, each of which is adapted togenerate images preferably digital images used to verify the identityand geometry of the drill bit as well as conduct initial and finalinspections or evaluations of the cutting tip 12 and fluted portion 14of a drill bit 16 inserted thereinto, as will be described in moredetail below. The optical assemblies 118 are each attached to the topsurface 44 of the housing 42 and are disposed under respective ones ofthe cassette trays 54.

As best seen in FIG. 7, each of the optical assemblies 118 comprises anoptical housing 120 having a circularly configured opening 122 disposedwithin one of the sidewalls thereof. The opening 122 is sized andconfigured to receive the locking sleeve 111 of one of the workheadassemblies 96. When the optical assemblies 118 are mounted to thehousing 42, the distance separating the opening 122 of each opticalhousing 120 from the top surface 44 of the housing 42 is such that thecollet axis CX of one of the workhead assemblies 96 may be coaxiallyaligned with the opening 122. Such alignment is needed to allow a drillbit 16 held within the collet head 110 of a workhead assembly 96 to beinsertable into the interior of the optical housing 120 via the opening122 upon the movement of the base member 98 of the workhead assembly 96along the base member axis BX.

Disposed within the interior of the optical housing 120 is a circularlyconfigured illumination ring or array 124 which is coaxially alignedwith the opening 122. The illumination array 124 preferably comprises asequential ring of LED's which emit red light. Attached to the sidewallof the optical housing 120 opposite that including the opening 122disposed therein is a front camera 126 of the optical assembly 118. Thefront camera 126 protrudes into the interior of the optical housing 120,and includes a circularly configured lens which is coaxially alignedwith both the opening 122 and the illumination array 124. In addition tothe front camera 126, each optical assembly 118 includes a top camera128 which is attached to the top of the optical housing 120. Like thefront camera 126, the top camera 128 protrudes into the interior of theoptical housing 120, and includes a circularly configured lens whichextends in generally perpendicular relation to the collet axis CX when adrill bit 16 is inserted into the interior of the optical housing 120 bya workhead assembly 96. Although various optical systems arecontemplated herein, a preferred system is manufactured by Volution,Inc. of San Diego, Calif.

Grinding Assemblies

Referring now to FIGS. 2, 3 and 8, the apparatus 10 further comprises apair of grinding assemblies 130 which are attached to the top surface 44of the housing 42. Each of the grinding assemblies 130 comprises agrinder mount 132 which-has a generally U-shaped configuration. Movablyattached to the grinder mount 132 and disposed between the end portionsdefined thereby are first and second grinder motors 134, 136. Rotatablyconnected to the first grinder motor 134 is a first circularlyconfigured grinding head 138, while rotatably connected to the secondgrinder motor 136 is a second circularly configured grinder head 140.

In the apparatus 10, the grinding faces of the first and second grinderheads 138, 140 typically do not extend in perpendicular relation to thetop surface 44 of the housing 42, but rather are angularly off-setrelative thereto. In each grinding assembly 130, the angularorientations of the grinding faces of the first and second grinder heads138, 140 relative to the top surface 44 may be selectively adjusted. Inthis respect, the grinder mount 132 includes a pair of accurately shapedslots 142 disposed within respective ones of the end portions definedthereby. The attachment of the first and second grinder motors 134, 136to the grinder mount 132 is facilitated by the receipt of mountingshafts extending from each of the first and second grinder motors 134,136 into respective ones of the slots 142. The tightening of a clampingmember 144 disposed on the distal end of at least one of the mountingshafts maintains the mounting shafts in a desired location within theslots 142. As will be recognized, the loosening of the clamping member144 allows the location of the mounting shafts within the slots 142 tobe selectively adjusted as needed to alter the angular orientations ofthe grinding faces of the first and second grinder heads 138, 140relative to the top surface 44 of the housing 42. In each grindingassembly 130, the first and second grinder motors 134, 136 areinterconnected, and thus move in unison when the angular orientations ofthe grinding faces of the first and second grinder heads 138, 140 areadjusted in the above-described manner.

Referring now FIG. 13, each of the grinding assemblies 130 of theapparatus 10 may be optionally outfitted with a pair of adjustmentmechanisms 300. Each of the adjustment mechanisms 300 comprises ahousing 302 which has a generally rectangular configuration and definesa hollow interior. Extending longitudinally through the hollow interiorof the housing 302 is an elongate ball screw 304 which is rotatablymounted within each of the opposed, lateral sidewalls of the housing302. Mechanically coupled to one end of the ball screw 304 is a steppermotor 306 which is itself mounted to the outer surface of one of thelateral sidewalls of the housing 302. The stepper motor 306, whenactivated, is operative to selectively rotate the ball screw 304 ineither a first direction or a second direction which is opposite thefirst direction.

Each adjustment mechanism 300 further comprises a linear bearing 308which has a generally rectangular configuration and includes acantilever member 310 mounted to one of the opposed lateral sidesthereof. The cantilever member 310 is itself cooperatively engaged tothe ball screw 304 via a ball nut 312 disposed on the end thereofopposite that attached to the linear bearing 308. As shown in FIG. 13,mounted to the outer surface of the linear bearing 308 is the firstgrinder motor 134. Extending from the first grinder motor 134 is a firstrotatable motor shaft 135 which includes the first grinder head 138attached to the distal end thereof. As will be recognized, tile firstmotor shaft 135 facilitates the rotatable connection of the firstgrinder head 138 to the first grinder motor 134.

Due to the mounting of the first grinder motor 134 to the linear bearing308, the activation of the stepper motor 306 is operative to selectivelymove the first grinder motor 134, and hence the first grinder head 138,back and forth along the grinder head axis GH shown in FIG. 13. In thisrespect, the rotation of the ball screw 34 in the first directionfacilitates the movement of the first grinder head 138 along the grinderhead axis GH in a direction away from the stepper motor 306. Conversely,the rotation of the ball screw 304 in the second direction opposite thefirst direction facilitates the movement of the first grinder head 138along the grinder head axis GH in a direction toward the stepper motor306. The advantages attendant to the ability to move the first grinderhead 138 back and forth along the grinder head axis GH will be discussedin more detail below. Though not shown, the adjustment mechanism 300 mayfurther include a spring which is disposed within the interior of thehousing 302 and cooperatively engaged to the linear bearing 308 forpurposes of applying a pre-load thereto.

As will be recognized, in the alternative grinding assembly 130including the adjustment mechanisms 300, the second grinder motor 136 ismounted to the outer surface of the linear bearing 308 of the other,remaining adjustment mechanism 300. The adjustment mechanisms 300, andin particular the housings 300 thereof, may be attached to a modifiedversion of the grinder mount 132 which is sized and configured toaccommodate the same.

Secondary Cleaning Assemblies

Referring now to FIGS. 2, 3 and 8 a, the apparatus 10 further comprisesa pair of secondary cleaning assemblies 180 which are attached to thetop surface 44 of the housing 42 outwardly of respective ones of thecassette trays 54. The secondary cleaning assemblies 180 are used tofacilitate the cleaning of the cutting tip 12 of a drill bit 16 prior tothe final inspection thereof by one of the optical assemblies 118 aswill be described in more detail below.

Each of the secondary cleaning assemblies 180 comprises a base member182 which is attached to the top surface 44 of the housing 42. Movablyattached to the base member 182 is an elongate conveyor bar 184 whichincludes a pair of conveyor rollers 186 rotatably connected to a commonside thereof in relative close proximity to respective ones of theopposed ends thereof. Attached to one of the conveyor rollers 186 is anindexing wheel 188, while extending about the conveyor rollers 186 is acontinuous conveyor belt 190. Additionally, attached to the base member182 is an indexing member 192 which extends upwardly toward the indexingwheel 188. As seen in FIG. 8 a, the conveyor belt 190 is provided withquantities of cleaning putty 194 thereon, with each such quantity ofcleaning putty 194 being disposed between a respective pair of ribsformed on the conveyor belt 190.

In each secondary cleaning assembly 180, the base member 182 is operableto selectively actuate the conveyor bar 184, and hence the conveyor belt190, between a retracted position as shown in FIG. 8 a and an extendedposition as shown in phantom in FIG. 8 a. When the conveyor belt 190 isin the extended position, one of the quantities of cleaning putty 194disposed thereon is in general horizontal alignment with the axis of theopening 122 of a respective one of the optical assemblies 118. When theconveyor belt 190 is in its retracted position, the quantities ofcleaning putty 194 disposed thereon are oriented substantially below theaxis of the opening 122. Importantly, the movement of the conveyor belt190 from its extended position to its retracted position results in theengagement of the distal end of the indexing member 192 to the indexingwheel 188 in a manner facilitating the indexing of the conveyor belt 190a prescribed incremental distance. This movement of the conveyor belt190 effectively places a successive quantity of cleaning putty 194 intohorizontal alignment with the collet axis CX when the same is coaxiallyaligned with the opening 122 of the associated optical assembly 118.

Bumping Assembly

Referring now to FIGS. 2, 3 and 9, the apparatus 10 further comprises abumping assembly 146 which is attached to the top surface 44 of thehousing 42 substantially intermediate the cassette trays 54. The bumpingassembly 146 is used to facilitate the re-positioning of the locatingring 22 upon a drill bit 16 if needed subsequent to the completion ofthe re-sharpening of the cutting tip 12 of the drill bit 16. Thecomplete structure and manner of operation of the bumping assembly 146is described in detail in U.S. Pat. No. 5,472,298 entitled LOCATING RINGPOSITIONING APPARATUS FOR RE-SHARPENED DRILL BIT issued Dec. 5, 1995,the entire disclosure of which is incorporated herein by reference.

The bumping assembly 146 generally comprises a drill seat or anvil 148which is attached to the top surface 44 of the housing 42. Extendingaxially through the drill seat 148 is an aperture 150 for slidablyreceiving the shank portion 18 of a drill bit 16. The diameter of theaperture 150 is sized so as to slightly exceed the diameter of the shankportion 18, thus facilitating the slidable receipt of the shank portion18 thereinto. In addition to the drill seat 148, the bumping assembly146 has a reciprocal ram or hammer assembly which includes an enlargedtool head 152. The tool head 152 defines a central aperture 154extending axially therethrough which is slightly larger in diameter thanthe aperture 150 extending axially through the drill seat 148. Thecentral aperture 154 of the tool head 152 is coaxially aligned with theaperture 150, and thus in coaxial alignment with the longitudinal axisof a drill bit 16 inserted into the drill seat 148.

As seen in FIG. 9, the distal portion of the central aperture 154 isenlarged in size to partially receive the locating ring 22 positionedupon a drill bit 16. In this respect, the diameter of the enlargedportion slightly exceeds the diameter of the locating ring 22, with thedepth D2 of the enlarged portion being slightly less than the width W1of the locating ring 22. As further seen in FIG. 9, the enlargement ofthe distal portion of the central aperture 154 facilitates the formationof an annular bumping surface 156 which circumvents the reduced diameterportion of the central aperture 154, and is adapted to contact thelocating ring 22. As will be described in more detail below, when adrill bit 16 is inserted into the drill seat 148 and the ram assembly isactuated to facilitate the downward movement of the tool head 152, thecutting tip 12, fluted portion 14, tapered region 20 and upper end ofthe shank portion 18 of the drill bit 16 are received into the centralaperture 154, with the locating ring 22 being “bumped” by the bumpingsurface 156 so as to force the locating ring 22 into abutting contactwith the top surface 158 of the drill seat 148.

The bumping assembly 146 further comprises an adjustment mechanism forpositioning the cutting tip 12 of a drill bit 16 inserted into the drillseat 148 at a desired separation distance SD from the top surface 158 ofthe drill seat 148. The adjustment mechanism includes an opticalreference system which is adapted to produce a laser beam L whichtravels perpendicularly relative the longitudinal axis of the drill bit16 and is spaced from the top surface 158 of the drill seat 148 by theseparation distance SD. In addition to the optical reference system, theadjustment mechanism comprises a reversible linear actuator or steppermotor which is disposed within the interior of the housing 42 andincludes an elongate lead screw 160 which is selectively extensible fromand retractable into the stepper motor. Extending axially from the topend of the lead screw 160 is an elongate, cylindrically configured pinportion 162 which defines a blunt distal end. The diameter of the pinportion 162 is slightly less than the diameter of the aperture 150, thusallowing the pin portion 162 to be slidably extensible into the aperture150 and vertically moveable therewithin.

In the apparatus 10, the bumping assembly 146 is utilized by initiallyinserting the shank portion 18 of a drill bit 16 into the aperture 150of the drill seat 148 via the loader assembly 62. The insertion of theshank portion 18 into the aperture 150 is limited by the abutment of theend 24 thereof against the distal end of the pin portion 162 which, aspreviously indicated, resides within the aperture 150.

Subsequent to the insertion of the drill bit 16 into the drill seat 148,the optical laser beam L is transmitted horizontally, and moreparticularly perpendicularly relative the longitudinal axis of the drillbit 16 inserted into the drill seat 148. The laser beam L is oriented soas to be separated from the top surface 158 of the drill seat 148 by theseparation distance SD which is preferably the sum of the distance D1and the width W1 of the locating ring 22. When the drill bit 16 isinitially inserted into the drill seat 148, the cutting tip 12 istypically disposed above the level of the laser beam L. As such, sincethe cutting tip 12 must be positioned at the separation distance SDprior to bumping the locating ring 22, the drill bit 16 must typicallybe lowered within the drill seat 148 so as to precisely position thecutting top 12 within the laser beam L.

The lowering of the drill bit 16 within the drill seat 148 isaccomplished by activating the stepper motor in a manner causing thelead screw 160 to move in a downward vertical direction, which in turncauses the distal end of the pin portion 162 to move downwardly withinthe aperture 150. Since the bottom end 24 of the shank portion 18 isabutted against the pin portion 162 when the drill bit 16 is initiallyinserted into the drill seat 148, the downward movement of the pinportion 162 causes the shank portion 18 to be retracted into the drillseat 148, thus lowering the level of the cutting tip 12.

The downward vertical movement of the lead screw 160 is continued tosuch time as the cutting tip 12 is disposed below the laser beam L. Whenit is determined that the cutting tip 12 is disposed below the level ofthe laser beam L (i.e., a continuous laser beam L is transmitted anduninterrupted by the cutting tip 12), the stepper motor is deactivatedand the downward vertical movement of the lead screw 160 stopped.Thereafter, the stepper motor is re-energized in a manner facilitatingthe upward vertical movement of the lead screw 160 and pin portion 162thereof. The upward movement of the lead screw 160 facilitates thesimultaneous upward movement of the cutting tip 12 toward the laser beamL. At the precise moment the cutting tip 12 interrupts the laser beam L,the stepper motor is deactivated, thus resulting in the cutting tip 12being spaced from the top surface 158 of the drill seat 148 by theseparation distance SD.

When the cutting tip 12 is positioned within the laser beam L and thusspaced from the top surface 158 by the separation distance SD, a slightgap will typically be defined between the locating ring 22 and the topsurface 158 of the drill seat 148. Thereafter, the ram assembly isactuated to facilitate the rapid downward movement of the tool head 152.As previously indicated, the downward actuation of the tool head 152results in the locating ring 22 being contacted or “bumped” by thebumping surface 156 defined about the central aperture 154. Importantly,the bumping of the locating ring 22 by the tool head 152 overcomes thefrictional or press-fit engagement of the locating ring 22 upon theshank portion 18 of the drill bit 16 and forces the locating ring 22downwardly into abutting contact with the top surface 158 of the drillseat 148. Once the locating ring 22 is abutted against the top surface158, it is spaced from the cutting tip 12 at the desired distance D1.The locating ring 226 is preferably bumped twice by the tool head 152,with the first bump being utilized to force the locating ring 22 inabutting contact with the top surface 158, and the second bump beingutilized to jettison any residual flash or debris from the locating ring22.

As seen in FIGS. 2 and 3, ram assembly of the bumping assembly 146 ismovably mounted to a base carriage 164 of the bumping assembly 146 andlinearly moveable between extended and retracted positions relative tothe drill seat 148. When the ram assembly is in its extended position,the central aperture 154 of the tool head 152 is coaxially aligned withthe aperture 150 of the drill seat 148. Conversely, when the ramassembly is actuated to its retracted position (as shown in FIGS. 2 and3), the same is spaced horizontally away from the drill seat 148, thusproviding access to the aperture 150 to allow the loader assembly 62 toinsert the drill bit 16 thereinto in the above-described manner.

Apparatus Operation

Having thus described the various assemblies of the apparatus 10, theoperation thereof will now be explained with reference to FIGS. 11 a-11n. In the apparatus 10, the programmable control device(s) disposedwithin either or both of the control panels 46 or within the interior ofthe housing 42 functions to control and coordinate the operations of theloader assembly 62, inversion assemblies 85, workhead assemblies 96,optical assemblies 118, grinding assemblies 130, secondary cleaningassemblies 180, and bumping assembly 146. In this respect, the controldevice is electrically interfaced to the various components of theseassemblies (e.g., first and second stepper motors 104, 112, front andtop cameras 126, 128, first and second grinder motors 134, 136), and toauxiliary control devices such as solenoid valves, cylinders and thevacuum pump which are used to facilitate the control of other componentsof the assemblies.

In the following discussion of the operation of the apparatus 10, thesequence of steps will be described in relation to the re-sharpening ofthe cutting tip 12 of a drill bit 16 and the re-positioning of thelocating ring 22 thereof through the use or one of the cassette trays54, the loader assembly 62, one of the shaft members 72 of the gripper70, one of the primary cleaning assemblies 80, one of the inversionassemblies 85, one of the workhead assemblies 96, one of the opticalassemblies 118, one of the grinding assemblies 130, one of the secondarycleaning assemblies 180, and the bumping assembly 146. However, those ofordinary skill in the art will recognize that since the apparatus 10includes pairs of primary cleaning, workhead, optical, grinding andsecondary cleaning assemblies as well as a pair of shaft members 72 onthe gripper 70 and a pair of cassette trays 54, the cutting tipre-sharpening and locating ring re-positioning processes as willhereinafter be described may be conducted simultaneously on at least twodrill bits 16, with the control device being specifically adapted tocontrol and coordinate such simultaneous operations.

In using the apparatus 10, a drill bit container 26 including aplurality of drill bits 16 stored therewithin is positioned within anopening 56 of a cassette tray 54, with the cover 30 of the drill bitcontainer 26 being moved to its opened position or removed from the base28, thus exposing the fluted portions 14 of the drill bits 16 (FIG. 11a). Thereafter, a single drill bit 16 is lifted out of the drill bitcontainer 26 by the loader assembly 62, and in particular a shaft member72 of the gripper 70. (FIG. 11 b). The manner in which the loaderassembly 62 functions to grasp and release a drill bit 16 is describedabove in the section captioned Loader Assembly. As will be recognized,the control device of the apparatus 10 is programmed in a manner whichallows the same to maneuver a shaft member 72 of the gripper 70 intoaxial alignment with any drill bit 16 in a drill bit container 26 storedwithin any opening 56 of a cassette tray 54.

After being lifted out of the drill bit container 26, when necessary,the drill bit 16 is transported by the loader assembly 62 to aninversion assembly 85, and is inserted by the loader assembly 62 intothe holder block 88 of the inversion arm 87 stitch that the flutedportion 14 is directed generally vertically upwardly (FIG. 11 c). Theinsertion of the drill bit 16 into the holder block 88 is accomplishedin the manner previously described in the section captioned InversionAssemblies. After the drill bit 16 has been inserted into the holderblock 88 and the locking pin 89 extended so as to engage the shankportion 18 and lock the drill bit 16 within the holder block 88, theinversion arm 87 is rotated approximately 180° such that the shankportion 18 of the drill bit 16 is directed generally verticallyupwardly. The drill bit 16 is then removed from within the holder block88 by the loader assembly 62 in the manner also previously described inthe section captioned Inversion Assemblies.

After the drill bit 16 has been removed from within the holder block 88of an inversion assembly 85, the drill bit is transported by the loaderassembly 62 to a primary cleaning assembly 80, with the cutting tip 12then being inserted into and removed from within the cleaning putty 84via the loader assembly 62 to facilitate the cleaning thereof in themanner previously described in the section captioned Primary CleaningAssemblies. The drill bit is then transported back to an inversionassembly 85 and inserted by the loader assembly 62 into the holder block88 such that the shank portion 18 is directed generally verticallyupwardly. Once again, the insertion of the drill bit 16 into the holderblock 88 is accomplished in the manner previously described in thesection captioned Inversion Assemblies. After the drill bit 16 has beeninserted into the holder block 88 and the locking pin 89 extended so asto engage the shank portion 18 and lock the drill bit 16 within theholder block 88, the inversion arm 87 is rotated approximately 180° suchthat the fluted portion 14 is directed generally vertically upwardly.The drill bit 16 is then re-grasped by the loader assembly 62 andremoved from within the holder block 88 of the inversion assembly 85(FIG. 11 e) in the manner previously described in the section captionedInversion Assemblies.

As previously explained, if the drill bit 16 is initially orientedwithin the drill bit container 26 such that the shank portion 18 ratherthan the fluted portion 14 thereof is directed generally verticallyupwardly, the step of inverting or flipping the drill bit 16 prior tothe initial cleaning of the cutting tip 12 thereof as shown anddescribed in relation to FIG. 11 c is eliminated since the flutedportion 14 (as opposed to the shank portion 18) already protrudes fromthe shaft member 72. In this respect, the operational sequence of theapparatus 10 proceeds directly from the removal of the drill bit 16 fromwithin the drill bit container 26 as shown and described in relation toFIG. 11 b to the cleaning of the cutting tip 12 in the manner shown anddescribed in relation to FIG. 11 d. The inversion step conductedsubsequent to the initial cleaning of the cutting tip 12 as shown anddescribed in relation to FIG. 11 e must always be completed irrespectiveof the initial orientation of the drill bit 16 within the drill bitcontainer 26.

After the drill bit 16 has been lifted out of the holder block 88, theactuator member 78 of the gripper 70 is activated so as to rotate theshaft members 72 upwardly in a manner causing the drill bit 16 to extendalong the gripper axis GX (FIGS. 4 a and 11 f). The loader assembly 62is then maneuvered so as to axially align the gripper axis GX with thecollet axis CX of a workhead assembly 96. Subsequent to such alignment,the shank portion 18 of the drill bit 16 is horizontally advanced intothe collet head 110 of the collet member 106 of the workhead assembly 96and locked therein (FIG. 11 g).

When the drill bit 16 is initially inserted into the collet head 110,the orientation of the swivel member 102 and hence the collet member 106of the workhead assembly 96 is such that the collet axis CX is coaxiallyaligned with the opening 122 within the optical housing 120 of anoptical assembly 118. The actuator 100 of the workhead assembly 96 isthen activated to cause the retraction of the piston rod into the body,thus resulting in the movement of the base member 98 of the workheadassembly 96 along the base member axis BX toward the optical assembly118. Such movement is continued until such time as the fluted portion 14and cutting tip 12 of the drill bit 16 are properly positioned withinthe interior of the optical housing 120 of the optical assembly 118(FIGS. 7 and 11 h).

Referring now to FIGS. 7 a-7 d, the movement of the drill bit 16 intothe optical assembly 118 causes the control device to trigger theperformance of a verification of the identity and geometry of the drillbit 16 and the initial inspection or evaluation of the fluted portion 14and cutting tip 12 by the optical assembly 118. As will discussed inmore detail below, the optical assembly 118 is provided with controllogic having unique operative capabilities in relation to the inspectionor evaluation and measurement of the cutting tip 12 of the drill bit 16.In the apparatus 10, each optical assembly 118 is in electricalcommunication with the control device for purposes of transmitting datapertaining to such evaluations and measurements thereto so as to providethe apparatus 10 of the present invention with statistical processcontrol (SPC) capability. The electrical communication between thecontrol logic of the optical assembly 118 and the control device of theapparatus 10 also allows for the selective activation and deactivationof the actuator 100 and first and second stepper motors 104, 112 of thecorresponding workhead assembly 96 as is needed to facilitate theindexing of the cutting tip 12 within the optical assembly 118 in aprescribed manner which will also be discussed in more detail below.

Referring now FIG. 7 a, during the set-up of the apparatus 10, theoverall length (OAL) of the drill bit 16 as new is known and programmedor inputted into the control device. As the cutting tip 12 and flutedportion 14 of the drill bit 16 are being advanced into the interior ofthe optical assembly 118, the top camera 128 thereof begins generatingimages of the cutting tip 12 and the fluted portion 14 for purposes ofallowing the same to be oriented in a prescribed manner relative tovarious reference points established by the control logic of the opticalassembly 118. More particularly, as seen FIGS. 7 a-7 d, the controllogic of the optical assembly 118 is operative to produce a first set ofcross-hairs consisting of a first reference axis RA1 and a secondreference axis RA2 which extend perpendicularly relative to each otherand are superimposed on the images generated by the top camera 128. Asseen in FIGS. 7 a and 7 c, the first set of cross-hairs are generated bythe control logic of the optical assembly 118 such that the secondreference axis RA2 extends in parallel relation to the collet axis CX.Thus, as the drill bit 16 is advanced into the optical assembly 118, thecutting tip 12 is advanced along the second reference axis RA2.

As indicated above, the overall length of a new drill bit 16 is knownand inputted into the control device of the apparatus 10. When the drillbit 16 is initially advanced into the optical assembly 118, the controldevice, using the data transmitted thereto from the optical assembly118, is operative to continue the movement of the base member 98 of theworkhead assembly 96 along the base member axis BX until such time asthe chisel edge 200 of the cutting tip 12 of a new drill bit 16 would bedisposed at the point at which the first and second reference axes RA1,RA2 intersect. However, as seen in FIG. 7 a, since the apparatus 10 isadapted for use in re-sharpening drill bits, the drill bit 16 advancedinto the optical assembly 118, due to its prior usage, will typicallynot be of the same overall length as a new drill bit 16, but ratherslightly shorter in length. Thus, when the movement of the work assembly96 along the base member axis BX is stopped or discontinued, the chiseledge 200 of the cutting tip 12 will typically fall short of theintersection point between the first and second reference axes RA1, RA2due to the reduced length of the fluted portion 14 attributable to theprior usage of the drill bit 16.

After the movement of the workhead assembly 96 has been discontinued,the control logic of the optical assembly 118 is operative to measure ordetermine the distance DL separating the chisel edge 200 of the cuttingtip 12 from the intersection point between the first and secondreference axes RA1, RA2. This distance DL as determined by the opticalassembly 118 is transmitted to the control device, thus allowing thecontrol device to calculate the actual overall length of the drill bit16 within the optical assembly 118. The actual overall length is derivedby subtracting the distance DL from the new drill length measurementpreviously input into the control device. The calculated actual overalllength of the drill bit 16 is stored within the control device of theapparatus 10. Subsequent to this calculation of the overall length ofthe drill bit 16, the control device of the apparatus 10 re-initiatesthe movement of the workhead assembly 96 along the base member axis BX.More particularly, the workhead assembly 96 is caused to move the drillbit 16 through the distance DL so as to place the chisel edge 200 of thecutting tip 12 at the intersection point of the first and secondreference axis RA1, RA2.

Referring now to FIG. 7 b, after the cutting tip 12 of the drill bit 16has been indexed forwardly by the control device in the above-describedmanner, images of the cutting tip 12 of the drill bit 16 are thengenerated by the front camera 126 of the optical assembly 118. Thecontrol logic of the optical assembly 118 is further operative togenerate a second set of cross-hairs consisting of a generallyhorizontal third reference axis RA3 and a generally vertical fourthreference axis RA4 which extend perpendicularly relative to each otherand are superimposed on the images generated by the front camera 126.The second set of cross-hairs are produced by the control logic of theoptical assembly 118 such that the intersection point between the thirdand fourth reference axis RA3, RA4 is oriented upon the collet axis CX.As is seen in FIG. 7 b, the control logic of the optical assembly 118 isfurther operative to determine or measure the diameter D of the drillbit 16 through the use of the images generated by the front camera 126.The diameter D as determined by the control logic of the opticalassembly 118 is transmitted to and stored within the control device ofthe apparatus 10. Additionally, as seen in FIG. 7d, by using or focusingon the primary faces or facets 204 of the cutting tip 12, the controllogic of the optical assembly 118 is operative to establish a referenceline RL which extends generally along the straight sections of thecutting edges 202 of the cutting tip 12.

Subsequent to the establishment of the reference line RL, the controllogic of the optical assembly 118 is operative to determine or measurethe angle A between the reference line RL and the third reference axisRA3 of the second set of cross-hairs. The measured angle A istransmitted to and stored within the control device along with themeasurement of the diameter D and previously calculated overall lengthof the drill bit 16. It is preferred that the angle A be less than 90degrees. If the angle A is determined to be outside of this desiredrange, the control device is operative to facilitate the rotation of thecollet shaft 108 and hence the collet head 110 via the second steppermotor 112, thus resulting in the rotation of the drill bit 16 relativeto the collet axis CX. The rotation of the drill bit 16 relative to thecollet axis CX is continued until it is determined by the control logicof the optical assembly 118 that the angle A is within the desiredrange. Once the angle A is within the desired range, the specificmeasurement thereof is transmitted to and stored within the controldevice.

Referring now to FIG. 7 c, subsequent to the measurement of the angle A,images are once again generated by the top camera 128 of the opticalassembly 118. Based on these generated images, the control logic of theoptical assembly 118 is operative to identify the margins of the drillbit 16, and to establish or generate a target line TL which extendsgenerally along one of the margins and over the distal end or edgethereof defined at the cutting tip 12. In addition to the target line TLbeing produced by the control logic of the optical assembly 118, theimages generated by the top camera 128 are used to cause the controldevice to facilitate a slight incremental movement of the workheadassembly 96 along the base member axis BX. More particularly, the drillbit 16 is moved forwardly along the second reference axis RA2 until itis determined by the control logic of the optical assembly 118 that thefirst reference axis RA1 extends generally along the distal ends oredges of both margins of the drill bit 16. Thereafter, the controldevice is operative to facilitate the rotation of the collet shaft 108and hence the drill bit 16 relative to the collet axis CX, with suchrotation being continued until the target line TL, crosses or intersectsthe point of intersection between the first and second reference axesRA1, RA2 of the first set of cross-hairs. It is contemplated that inaddition to generating the target line TL relative to one of the marginsof the drill bit 16, the control logic of the optical assembly 118 willfurther be operative to conduct an initial evaluation of the conditionof the margins of the drill bit 16, and in particular the portionsthereof adjacent the cutting tip 12. Data corresponding to this initialevaluation will be transmitted to and stored within the control device.

As will be recognized, the rotation of the drill bit 16 to facilitatethe passage of the target line TL across the point of intersection ofthe first and second references axes RA1, RA2 of the first set ofcross-hairs will result in a change to the previously measured angle A.However, the control device of the apparatus 10, working in conjunctionwith the control logic of the optical assembly 118, is able to calculatethe new angle A of the reference line RL relative to the third referenceaxis RA3 resulting from the rotation of the drill bit 16 in accordancewith the step shown in FIG. 7 c. As is discussed below, the stored newangle A is used as a baseline setting to facilitate the later adjustmentof the angle A as is needed to facilitate the proper engagement of thecutting tip 12 to the grinding assembly 130 and the proper illuminationof the cutting 12 within the optical assembly 118 during the finalinspection or evaluation thereof.

The adjustments to the angular orientation of the cutting tip 12 as maybe used to establish the angle A in the desired range and/or theextension of the target line TL through the point of intersection of thefirst and second reference axis RA1, RA2 is preferably accomplishedthrough a first rough rotation of the collet shaft 108 of the workheadassembly 96, which is immediately followed a fine rotation thereof.Importantly, the workhead assembly 96, and more particularly the secondstepper motor 112 thereof, is operable to provide positional accuracy tothe angular orientation of the cutting tip 12 to within about 0.000005inches.

It is contemplated that if either the calculated overall lengthmeasurement of the drill bit 16 or the diameter D thereof is initiallydetermined to be outside of specified tolerances, the drill bit 16 willimmediately be rejected from further processing. Similarly, if theinitial evaluation of the margin condition of the drill bit 16demonstrates that one or both of the margins are outside of a prescribedtolerance, the drill bit 16 will be rejected from further processingwithin the apparatus 10. Thus, ill the apparatus 10 of the presentinvention, the drill bit 16, and in particular the cutting tip thereof,is subjected to various initial qualifications, and is rejected prior toany re-grinding if such initial qualifications are not properlysatisfied. Thus, as indicated above, a parameter such the actual overalllength of the drill sit 16 may be used to determine whether the cuttingtip 12 thereof should be re-ground or whether the drill bit 16 should bethrown-out.

As explained above, the control logic of the optical assembly 118 isoperable to process and interpret the images generated by the front andtop cameras 126, 128. Due to the optical assembly 118 being inelectrical communication with the control device and operative totransmit data corresponding to the images generated by the front and topcameras 126, 128 thereto, the control device is able to regulate themovement of the workhead assembly 96 (i.e., the movement of the basemember 98 along the base member axis BX and/or the rotation of thecollet shaft 108 about the collet axis CX) in response to such data asis needed to accomplish the indexing and adjustment steps described inrelation to FIGS. 7 a-7 d. As also indicated above, the data obtainedfrom the initial evaluation of the drill bit 16 (i.e., the overalllength, diameter D, angle A and margin condition) is stored within thecontrol device for future reference and for purposes of updating theartificial intelligence of the control device. During the initialevaluation process, the fluted portion 14 and cutting tip 12 of thedrill bit 16 are properly illuminated via the illumination array 124 ofthe optical assembly 118.

Subsequent to the completion of the initial evaluation of the drill bit16, the same is retracted out of the optical assembly 118 by theworkhead assembly 96 and transported to a grinding assembly 130 thereby.As indicated above, the angle A between the reference line RL and thirdreference axis RA3 is determined by the control logic of the opticalassembly 118 through the use of the images generated by the front camera126, with the angle A being transmitted to and stored within the controldevice. Upon the retraction of the drill bit 16 out of the opticalassembly 118, the control device is operative to facilitate the rotationof the drill bit 16 relative to the collet axis CX such that the angle Ais set to about 72 degrees. Importantly, the angle A is set to 72degrees so as to facilitate the engagement of the cutting tip 12 to thegrinding assembly 130 at the proper angular orientation, as will bedescribed in more detail below.

The process of transporting the drill bit 16 to the grinding assembly130 is accomplished by the activation of the actuator 100 to cause theextension or advancement of the piston rod from the body which resultsin the movement of the base member 98 of the workhead assembly 96 alongthe base member axis BX away from the optical assembly 118. The swivelmember 102 of the workhead assembly 96 is then rotated by the activationof the first stepper motor 104 so as to place the cutting tip 12 or thedrill bit 16 at the proper angular orientation relative to the grindingface of the first grinder head 138 of the grinder assembly 130 based onthe initial evaluation thereof. The collet shaft 108 of the colletmember 106 of the workhead assembly 96 is then indexed toward thegrinding assembly 130 by the activation of the second stepper motor 112.The movement of the collet member 108 is controlled so as to place thecutting tip 12 of the drill bit 16 into contact with the rotatinggrinding face of the first grinder head 138 (FIG. 11 i). Importantly, aspreviously indicated, as the cutting tip 12 of the drill bit 16 is beingadvanced toward the grinder head 138, the locking sleeve 111 is receivedinto the aperture or support bushing 116 of the support member 114 ofthe workhead assembly 96. Such receipt prevents excessive vibration andor movement of the collet head 110 and hence the cutting tip 12 of thedrill bit 16 as the same is being ground.

After the cutting tip 12 has been placed into contact with the grindingface of the first grinder head 138, the second stepper motor 112 isactivated so as to facilitate a slight retraction of the collet shaft108 into the collet member housing 107 for purposes of creating a narrowgap between the cutting tip 12 and the grinding face. Thereafter, thesecond stepper motor 112 is activated so as to cause the collet shaft108 to rotate the drill bit approximately 180°. Subsequent to suchrotation, the second stepper motor 112 is activated so as to once againfacilitate the advancement of the collet shaft 108 from the colletmember housing 107 and return the cutting tip 12 of the drill bit 16into contact with the grinding face. As will be recognized, thisprocedure must be followed to achieve the sharpening of both flutes ofthe cutting tip 12.

After both flutes of the cutting tip 12 have been re-sharpened by thegrinding face of the first grinder head 138, the same process asdescribed above is repeated in relation to the grinding face of thesecond grinder head 140. In this respect, the cutting tip 12 of thedrill bit 16 is advanced by a workhead assembly 96 into contact with therotating grinding face of the second grinder head 140, retractedtherefrom and rotated approximately 180°, and subsequently advanced backinto contact with the grinding face of the second grinder head 140.During the complete grinding process, the grinding of the cutting tip 12via the grinding face of the first grinder head 138 accomplishes a“rough” grind, with the grinding of the cutting tip 12 via the grindingface of the second grinder head 140 accomplishing a “fine” grind.

As will be recognized, the advancement of the cutting tip 12 of thedrill bit 16 into contact with the rotating grinding face of either thefirst or second grinder heads 138, 140 by a workhead assembly 96 resultsin a certain amount of pressure being exerted by the cutting tip 12against a respective grinding face. The advancement of the cutting tip12 into contact with the grinding face too quickly or with too muchforce, or the exertion of excessive pressure by the cutting tip 12against the grinding face during the grinding operation after initialcontact has been established could result in the fracture of breakage ofthe drill bit 16 or the burning of the cutting tip 12 thereof. Toeliminate such susceptibility to breakage or burning, each grindingassembly 130 of the apparatus 10 may be outfitted with theabove-described adjustment mechanisms 300. Importantly, each of theadjustment mechanisms 300 is operative to retract a respective grindingface away from the cutting tip 12 of the drill bit 16 in the event thepressure exerted by the cutting tip 12 thereagainst exceeds a prescribedlevel. For example, in the adjustment mechanism 300 shown in FIG. 13,the exertion of compressive pressure bay the cutting tip 12 against thegrinding face of the first grinder head 138 above a prescribed levelwould trigger the activation of the stepper motor 306 to facilitate therotation of the ball screw 304 in a manner resulting in the movement ofthe first grinder head 138 along the grinder head axis GH toward thestepper motor 306, and hence away from the cutting tip 12 of the drillbit 16. As will recognized, such rearward movement of the first grinderhead 138 alleviates the excessive pressure condition which couldotherwise result in the fracture of burning of the cutting tip 12. Thedetermination of whether the pressure exerted by the cutting tip 12against the grinding face of the first grinder head 138 exceeds theprescribed level is established by a suitable transducer elementdisposed within the first grinder motor 134 and cooperatively engaged tothe first motor shaft 135. This transducer element is in electricalcommunication with the stepper motor 306 and, as indicated above, causesthe first grinder head 138 to be retracted away from the cutting tip 12in response to an excessive pressure condition. In the event theretraction of the first grinder head 138 away from the cutting tip 12results in the pressure level falling below an acceptable or tolerablerange, the stepper motor 306 will be re-activated to facilitate to themovement of the first grinder head 138 in an opposite direction towardthe cutting tip 12 so as to re-establish contact therebetween at apressure level within the acceptable range.

It will be recognized that the same functionality is achieved inrelation to the second grinder head 140 by mounting the second grindermotor 136 to the remaining adjustment mechanism 300. Like the firstgrinder motor 134, the second grinder motor 136 may include a pressuretransducer element which is cooperatively engaged to the associatedmotor shaft facilitating the rotatable connection of the second grinderhead 140 to the second grinder motor 136. It is contemplated that in theapparatus 10 of the present invention, the initialevaluations/measurements of the drill bit 16 and cutting tip 12 thereoffacilitated by the optical assembly 118 and control device may be usedto cause the control device to manipulate the workhead assembly 96 inmanner allowing the re-grinding operation to be completed in a mannerwherein the overall length of the drill bit 16 is reduced by only about0.002 inches. This level of accuracy is a significant improvement overprior art re-sharpening devices of lesser accuracy wherein there-grinding process typically results in a reduction in overall lengthof about 0.008 inches, thus significantly reducing the life span of thedrill bit.

After the cutting tip 12 has been re-sharpened by the grinding assembly130, the drill bit 16 is then maneuvered by the workhead assembly 96such that the collet axis CX is coaxially aligned with the opening 122within the optical housing 120 of an optical assembly 118. The conveyorbar 184 of a secondary cleaning assembly 180 is then actuated from itsretracted to its extended position, thus resulting in the placement of aquantity of cleaning putty 194 on the conveyor belt 190 into horizontalalignment with the cutting tip 12 of the drill bit 16. Thereafter, theactuator 100 of the workhead assembly 96 is actuated so as to cause theretraction of the piston rod into the body, thus resulting in themovement of the base member 98 of the workhead assembly 96 along thebase member axis BX toward the optical assembly 118. Such movement iscontinued until such time as the cutting tip 12 is inserted into thequantity of cleaning putty 194 upon the conveyor belt 190 of thesecondary cleaning assembly 180 (FIG. 11 j). Subsequent to suchinsertion, the conveyor, bar 134 is actuated back to its retractedposition, thus resulting in the removal of the cutting tip 12 fromwithin the quantity of cleaning putty 194.

As previously explained in the section captioned Secondary CleaningAssemblies, the return of the conveyor bar 184 to its retracted positionresults in the indexing of the conveyor belt 190 a prescribedincremental distance which insures that the cutting tips 12 ofsubsequently cleaned drill bits 16 will not be inserted into the sameportion of cleaning putty 194 as the previously cleaned drill bits 16.After the cutting tip 12 of the drill bit 16 has been re-cleaned, thedrill bit 16 is re-inserted into the optical assembly 118 (FIG. 11 k),with such insertion being accomplished in the same manner previouslydescribed in relation to FIG. 11 h. After being cleaned but prior tobeing re-inserted into the optical assembly 118, the drill bit 16 isrotated by the workhead assembly 96 relative to the collet axis CX so asto set the angle A to 160 degrees or 20 degrees. As will be recognized,the control device is operative to facilitate such precise rotation ofthe drill bit 16 due to the original value of the angle A being storedtherein. Importantly, the rotation of the drill bit 16 such that theangle A equals 160 degrees or 20 degrees is used to optimize theillumination of the cutting tip 12 thereof by the illumination ray 124when the drill bit 16 is re-inserted into the optical assembly 118, forreasons which will be discussed in more detail below.

Referring now to FIGS. 10 a-10 c, the re-insertion of the drill bit 16into the optical assembly 118 causes the control device to trigger theperformance of a final inspection or evaluation of the cutting tip 12and fluted portion 14 thereof. More particularly, immediately upon thedrill bit 16 being re-inserted into the optical assembly 118, the topcamera 128 begins generating images which allow the control logic of theoptical assembly 118 co interact with the control device in a mannercausing the chisel edge 200 of the cutting tip 12 to be brought to thepoint of intersection between the first and second reference axis RA1,RA2 of the first set of cross-hairs. The advancement of the chisel edge200 to this point of intersection allows the optical assembly 118 todetermine whether the drill bit 16 has been broken during the grindingor re-sharpening process. In this respect, if the drill bit 16 has beenbroken, the images generated by the top camera 128 will establish thatat least a portion of the fluted portion 14 including the cutting tip 12is missing from the drill bit 16.

Assuming that the drill bit 16 has not been broken as a result of thecheck thereof by the optical assembly 118, the process previouslydescribed in relation to FIG. 7 a is repeated for purposes ofdetermining or measuring the new overall length of the drill bit 16. Inthis respect, since the grinding process typically results in theshortening of the fluted portion 14, the comparison of the new overalllength of the drill bit 16 to the previously stored measurement thereofallows for a determination as to how much of the fluted portion 14 hasbeen removed by the grinding process. The new overall length of thedrill bit 16 calculated subsequent to the completion to the re-grindingof the cutting tip 12 thereof is also transmitted to and stored withinthe control device.

Subsequent to the determination of the new overall length of the drillbit 16, the front camera 126 then generates images which are used toinspect or check the geometry and condition of the cutting tip 12 (FIG.10 b). As seen in FIGS. 10 c and 12 a-12 j, the control logic of theoptical assembly 118 is operative to interpret and evaluate the imagesgenerated by the front camera 126 regarding the geometry and conditionof the cutting tip 12 and to electrically communicate data correspondingto such evaluation to the control device for storage therein.Importantly, the highly sophisticated level of functionality of theoptical assembly 118, and in particular the control logic thereof,allows for a determination of various conditions of the cutting tip 12,including:

-   -   1. the final margin condition of the fluted portion 14 (FIG. 10        c);    -   2. relatively minor, non-functional conditions including an        overlap condition which can impede the drill bit 16 from        centering correctly (FIG. 12 a), a gap condition which is        typically considered to be a is non-functional condition of the        drill bit 16 (FIG. 12 b), a negative condition which is        typically considered to be a non-functional defect with no        impact on the cutting action or symmetry of the drill bit 16        when held within the specification (FIG. 12 c), a flare        condition which is typically considered to be a non-functional        cosmetic defect (FIG. 12 d), and a hook condition which is        typically considered to be a non-functional condition which        could result in premature wear of the cutting tip 12 (FIG. 12        i); and    -   3. critical cutting edge conditions, including chips on the        primary cutting edges 202 of the cutting tip 12 which prevent        the drill bit 16 from cutting cleaning and efficiently (FIG. 12        e), a lay back condition (also referred to as negative rake)        which allows the centers of the cutting edges 202 to be the        leading cutting edges of the cutting tip 12 verses the corner        edges thereof (FIG. 12 f), an offcenter condition which is        characterized by a non-centralized chisel edge 200 and allows        for non-concentric drilling to occur (FIG. 12 g), and an offset        condition which is defined by a off-centered center line CL of        the cutting tip 12 (i.e., primary faces 204 of different        thicknesses) and allows for non-concentric drilling to occur        (i.e., holes out-of-round or mis-registered) (FIG. 12 h).

Once again, the control device is operable to process and interpret theimages generated by the front and top cameras 126, 128, and store thedata obtained from the final evaluation for verification of tolerances,for future reference, and for updating the artificial intelligence ofthe control device. If through this final inspection, the drill bit 16is determined to be outside of process tolerances, the drill bit isrejected from further processing at this time or re-evaluated foradditional re-sharpening procedures. In this respect, the failure of thedrill bit 16 to satisfy prescribed parameters as determined during thefinal evaluation thereof could be used to trigger the initiation of are-grinding operation in relation thereto. As part of the finalevaluation, a determination is made by the control device as to whetherthe position of the locating ring 22 upon the shank portion 18 must beadjusted due to the shortening of the fluted portion 14 resulting fromthe grinding process. As indicated above, the re-sharpening of thecutting tip 12 (i.e., the grinding process), will typically necessitatethe re-positioning of the locating ring 22 upon the shank portion 18 ofthe drill bit 16. It is contemplated that the drill bit 16 may beprovided with some type of last use indicator adjacent the locating ring22 for providing a visual indication that the drill bit 16 should not besubjected to another re-grinding operation.

Upon completion of the final evaluation, the drill bit 16 is transferredfrom the workhead assembly 96 back to the loader assembly 62 (FIG. 11l). As will be recognized, this process is accomplished in the reversemanner to that previously described in relation to FIG. 11 g. Since thegripper 70 includes a pair of shaft members 72, a drill bit 16 can beremoved from within a workhead assembly 96 and another drill bit 16(i.e., the drill bit 16 disposed within the remaining shaft member 72)inserted into the workhead assembly 96 without having to maneuver thegripper 70 back to one of the cassette trays 54. If, during the finalevaluation of the drill bit 16 it is determined that the geometry of thecutting tip 12 is flawed or faulted, upon the drill bit 16 beingtransferred back to the loader assembly 62, the same is immediatelytransported by the loader assembly 62 to a reject bin or similarlocation. Assuming that the cutting tip 12 is not flawed and thelocating ring 22 must be re-positioned, the loader assembly 62 thentransports the drill bit 16 to the bumper assembly 146, and inserts theshank portion 18 of the drill bit 16 into the drill seat 148 of thebumping assembly 146 (FIG. 11 m). The re-positioning of the locatingring 22 of the drill bit 16 by the bumping assembly 146 is accomplishedin the manner previously described in the section captioned BumpingAssembly.

After the locating ring 22 has been re-positioned via the bumpingassembly 146, the drill bit 16 is transported back to a cassette tray 54by the loader assembly 62. Importantly, the loader assembly 62 ismaneuvered by the control device so as to return the drill bit 16 to theprecise drill bit receiving hole 40 within the drill bit container 26from which it was initially removed by the loader assembly 62 (FIG. 11n), thus re-packaging the drill bit 16 within the container 26.

Statistical Process Control

As indicated above, for each drill bit 16 re-sharpened by the apparatus10 of the present invention, data corresponding to the geometry andcondition of the drill bit 16, and in particular the cutting tip 12thereof, is transmitted to the control device and stored therewithin.This data is generated by the control logic of the optical controlassembly 118 based on the images generated by the front and top cameras126, 128 thereof. The transmission of this data to the control device byvirtue of its electrical communication with the optical assembly 118allows the control device to manipulate the various linear and/orrotational movements of the workhead assembly 96 as needed to facilitatethe required indexing of the drill bit 16, and in particular the cuttingtip 12 thereof, within the interior of the optical assembly 118 forproper illumination, inspection and evaluation.

Typically, the apparatus 10 of the present invention will be used tore-sharpen large lots of the drill bits 16. Importantly, the controldevice is provided with memory or storage capacity sufficient to allowfor the storage of the above-described information for each individualdrill bit 16 of the lot to be re-sharpened through the use of theapparatus 10. As indicated above, the data for each drill bit 16 storedwithin the control device includes its pre-grinding overall length,pre-grinding diameter, pre-grinding margin condition, post-grindingoverall length, post-grinding margin condition, and post-grindinggeometry/condition of the cutting tip 12. Advantageously, the controldevice has the capability of accumulating this data for the entire lotof drill bits 16 being re-sharpened by the apparatus 10, and to providea print-out of such data to provide to the customer. The data presentedto the customer in print-out form is lot specific. This data not onlyprovides a verification of the accuracy of the re-grinding process, butalso apprises the customer with a used drill analysis (UDA). In thisrespect, the data provided in the print-out may be used to advise thecustomer that the drill bits 16 are being re-sharpened too early, andthat the same may be subjected to further use before re-sharpening isnecessary. This data can also be used to determine whether the stockremoval from the cutting tips 12 of the drill bits 16 should be reduced,whether the stock removal from the cutting tips 12 of the drill bits 16should be increased, and whether the speed of the first and secondgrinder motors 134, 136 should be increased or decreased. This data canfurther be used to facilitate the sorting of the drill bits 16 in adesired manner. For example, drill bits 16 within a certain overalllength range may be sorted or segregated to a prescribed location, withdrill bits 16 having cutting tips 12 of a similar condition being sortedinto a prescribed location.

Additional modifications and improvements of the present invention mayalso be apparent to those of ordinary skill in the art. Thus, theparticular combination of parts and steps described and illustratedherein is intended to represent only one embodiment of the presentinvention, and is not intended to serve as limitations of alternativedevices within the spirit and scope of the invention.

1. An automated method of re-sharpening a drill bit having a shankportion and a fluted portion which defines a pair of margins and acutting tip using an automated re-sharpening apparatus which includes atleast one grinding assembly, at least one optical assembly, at least oneworkhead assembly, and a loader assembly, the method comprising thesteps of: a) positioning at least one drill bit at a pick-up location;b) removing the drill bit from the pick-up location via the loaderassembly; c) transferring the drill bit from the loader assembly to theworkhead assembly; d) conducting an initial evaluation of the drill bitvia the optical assembly; e) grinding the cutting tip via the grindingassembly according to the initial evaluation; f) conducting a finalevaluation of the drill bit via the optical assembly; and g)transporting the drill bit from the workhead assembly to a drop-offlocation via the loader assembly.
 2. The method of claim 1 wherein step(g) comprises transporting the drill bit to a prescribed drop-offlocation according to the final evaluation thereof.
 3. The method ofclaim 1 wherein: step (a) comprises positioning multiple drill bits atthe pick-up location; step (b) comprises removing the drill bits fromthe pick-up location one at a time via the loader assembly; and step (g)comprises transporting the drill bits from the workhead assembly to thedrop-off location one at a time via the loader assembly.
 4. The methodof claim 3 wherein step (g) comprises sorting the drill bits bytransporting the drill bits to respective ones of multiple drop-offlocations according to each of the final evaluations thereof.
 5. Themethod of claim 3 wherein the automated re-sharpening apparatus furtherincludes a programmable control device electrically connected to thegrinding, optical, workhead, and loader assemblies for controlling andcoordinating the operations thereof, and: step (d) comprises storingdata corresponding to the initial evaluation of each of the drill bitsin the control device; and step (f) comprises storing data correspondingto the final evaluation of each of the drill bits in the control device.6. The method of claim 5 further comprising the step of: (h) generatinga statistical process control report based on the data stored in thecontrol device.
 7. The method of claim 5 further comprising the stepsof: h) generating a used drill profile based on the data stored in thecontrol device; and i) adjusting the manner in which the cutting tips ofsubsequently processed drill bits are ground in step (e) according tothe used drill profile.
 8. The method of claim 1 wherein step (d)comprises: 1) inserting the fluted portion into the optical assembly viathe workhead assembly; 2) determining the overall length of the drillbit; 3) determining the diameter of the cutting tip; 4) determining thecondition of the margins; 5) indexing the cutting tip to a prescribedposition; and 6) removing the fluted portion from within the opticalassembly via the workhead assembly.
 9. The method of claim 8 wherein theoptical assembly is operative to generate first, second, third, andfourth reference axes, and step (2) comprises: i) indexing the cuttingtip to a first reference point on the second reference axis via theworkhead assembly; and ii) determining the distance between the firstreference point and a point of intersection between the first and secondreference axes.
 10. The method of claim 9 wherein the optical assemblyis further operative to generate a reference line and a target line, andstep (5) comprises: i) generating the reference line along the cuttingtip of the drill bit; ii) rotating the drill bit via the workheadassembly to adjust the angular orientation of the reference linerelative to the third reference axis to within a prescribed range; iii)indexing the cutting tip to a second reference point on the secondreference axis; iv) generating the target line along one of the marginsof the fluted portion; and v) rotating the drill bit via the workheadassembly as needed to cause the target line to cross the point ofintersection between the first and second reference axes.
 11. The methodof claim 1 wherein step (h) comprises: 1) inserting the fluted portioninto the optical assembly via the workhead assembly; 2) determining theoverall length of the drill bit; 3) determining the geometry of thecutting tip; 4) determining the condition of the margins; and 5)removing the fluted portion from within the optical assembly via theworkhead assembly.
 12. The method of claim 11 wherein the opticalassembly is operative to generate first, second, third, and fourthreference axes, and step (1) comprises: i) indexing the cutting tip to afirst reference point on the second reference axis via the workheadassembly; and ii) determining the distance between the first referencepoint and a point of intersection between the first and second referenceaxes.
 13. The method of claim 1 wherein the automated re-sharpeningapparatus includes a pair of optical assemblies and a pair of grindingassemblies, and steps (a)-(g) are conducted simultaneously on at leasttwo drill bits.
 14. The method of claim 1 wherein step (e) comprises: 1)moving the cutting tip into contact with the grinding assembly via theworkhead assembly; 2) moving the cutting tip away from the grindingassembly via the workhead assembly; 3) rotating the cutting tipapproximately 180° via the workhead assembly; 4) moving the cutting tipinto contact with the grinding assembly via the workhead assembly; and5) moving the cutting tip away from the grinding assembly via theworkhead assembly.
 15. The method of claim 14 wherein steps (1) and (4)each comprise retracting the grinding assembly away from the cutting tipin the event the contact pressure between the cutting tip and thegrinding assembly exceeds a prescribed level.
 16. An automated method ofre-sharpening a drill bit having a shank portion and a fluted portionwhich define the pair of margins and a cutting tip using an automatedre-sharpening apparatus which includes a pair of grinding assemblies, apair of optical assemblies, a pair of workhead assemblies, and a loaderassembly, the method comprising the steps of: a) positioning multipledrill bits at a pick-up location; b) removing the drill bits from thepick-up location one at a time via the loader assembly; c) transferringthe drill bits from the loader assembly to respective ones of theworkhead assemblies; d) conducting initial evaluations of the drill bitsvia respective ones of the optical assemblies; e) grinding the cuttingtips via respective ones of the grinding assemblies according to theinitial evaluations; f) conducting final evaluations of the drill bitsvia respective ones of the optical assemblies; and g) transporting thedrill bits from the workhead assemblies to a drop-off location via theloader assembly.
 17. An automated method of re-sharpening a drill bithaving a shank portion and a fluted portion which defines a pair ofmargins and a cutting tip using an automated re-sharpening apparatuswhich includes at least one grinding assembly and at least one opticalassembly, the method comprising the steps of: a) conducting an initialevaluation of the drill bit via the optical assembly; b) grinding thecutting tip via the grinding assembly according to the initialevaluation; c) conducting a final evaluation of the drill bit via theoptical assembly; and d) generating and storing data corresponding tothe initial and final evaluations of the drill bit.
 18. The method ofclaim 17 wherein: step (a) comprises positioning multiple drill bits ata pick-up location and transporting the drill bits to the opticalassembly one at a time; step (b) comprises transporting each of thedrill bits from the optical assembly to the grinding assembly; step (c)comprises transporting each of the drill bits from the grinding assemblyto the optical assembly; and step (d) comprises sorting the drill bitsby transporting the drill bits to respective ones of multiple drop-offlocations according to the data generated and stored in relationthereto.
 19. An automated apparatus for re-sharpening a drill bit havinga shank portion and a fluted portion which defines a pair of margins anda cutting tip, the apparatus comprising: a) a housing; b) at least oneoptical assembly attached to the housing and operative to conductinitial and final evaluations of the drill bit; c) at least one grindingassembly attached to the housing and operative to grind the cutting tipaccording to the initial evaluation conducted by the optical assembly;d) at least one workhead assembly movably attached to the housingfor'selectively transporting the drill bit between the optical andgrinding assemblies; and e) a loader assembly movably attached to thehousing for selectively transporting the drill bit from a pick-uplocation to the workhead assembly and from the workhead assembly to adrop-off location.
 20. The apparatus of claim 19 further comprising aprogrammable control device electrically connected to the grinding,optical, workhead, and loader assemblies for controlling andcoordinating the operations thereof.
 21. The apparatus of claim 20wherein the optical assembly comprises: a) top and front cameras forgenerating images which are used to determine the overall length of thedrill bit, the diameter and geometry of the cutting tip, and thecondition of the margins, and to index the cutting tip to selectedreference points; b) an illumination array for illuminating the flutedportion and the cutting tip; and c) control logic which is operative toprocess and interpret the images generated by the top and front camerasand to interact with the control device in a manner regulating themovement of the workhead assembly in a prescribed manner based on thegenerated images.
 22. The apparatus of claim 20 wherein the grindingassembly comprises: a) at least one grinder motor; b) a grinder headrotatably connected to the grinder motor and defining a grinding face;and c) an adjustment mechanism attached to the grinder motor andoperative to selectively move the grinder head into and out of contactwith the cutting tip of the drill bit based upon the level of contactpressure exerted by the cutting tip against the grinding face.
 23. Theapparatus of claim 2 wherein the adjustment mechanism comprises: a) ahousing; b) an elongate ball screw rotatably mounted to the housing; c)a stepper motor mechanically coupled to the ball screw and operative toselectively rotate the ball screw in either a first direction or asecond direction opposite the first direction; and d) a linear bearingcooperatively engaged to the ball screw such that the rotation of theball screw in the first direction facilitates the movement of the linearbearing toward the workhead assembly and the rotation of the ball screwin the second direction facilitates the movement of the linear bearingaway from the workhead assembly; and the grinder motor being attached tothe linear bearing.
 24. The apparatus of claim 20 including: a pair ofgrinding assemblies attached to the housing; a pair of opticalassemblies attached to the housing; a pair of workhead assembliesattached to the housing; and the control device controlling andcoordinating the operations of the grinding, optical, workhead, andloader assemblies in a manner allowing the re-sharpening process to beconducted simultaneously on at least two drill bits.